Given the variability of recurrence risks observed in the family

Given the variability of recurrence risks observed in the family studies and the clinical heterogeneity that is evident in OCD, this result is not surprising. Nevertheless, it is noteworthy that the conclusions of the authors in all of these reports were that there are some genes of major effect important for the manifestation of OCD. Given the variability in the estimates of recurrence risks in the reported studies, it is quite likely that OCD is an oligogenic disorder (ie, a selleck chem number of genes are important for the expression of the disorder). In addition to advances in understanding

regarding inhibitor Sunitinib familiality and genetic mechanisms that are likely to be Inhibitors,research,lifescience,medical involved in OCD, there have also been dramatic gains in our understanding of the phenotype of OCD. Perhaps most important for genetic research are new ways to assess the phenotype dimensionally, moving beyond traditional categorical diagnostic classifications. Over Inhibitors,research,lifescience,medical the last decade, results from a number of independent

studies have demonstrated that there are different clusters of symptoms that comprise the OCD phenotype73-77 and that they appear to be heritable.73,76 It follows then that there may be several genes that could influence Inhibitors,research,lifescience,medical the different components of OCD. Candidate gene studies Given current theoretical understanding of mechanisms that may be implicated in the emergence and maintenance of OCD symptoms and the treatment of the disorder, a number of investigators have pursued genetic studies of specific genes that are known to be involved in systems implicated in the pathogenesis of OCD. In particular, because of the efficacy of serotonin reuptake in treating OCD,78-79 a number of genes important in the serotonergic system have been examined. In addition, genes in the dopaminergic, Inhibitors,research,lifescience,medical glutamatergic, and opioid systems have also been studied to determine if they also contribute to the risk Inhibitors,research,lifescience,medical of OCD.80 Over 80 candidate gene studies have been published over the last decade (Table III) . As noted above, association studies have examined candidate genes that function

within the serotonergic and dopaminergic systems and more recently the glutamatergic system based on knowledge of the pathophysiology and pharmacology of OCD. However, with the exception of the glutamate transporter gene SLCL1A1,81-84 none have been consistently replicated. Batimastat While some of the more recent published studies have larger sample sizes, all have inadequate sample sizes to achieve genome -wide significance (ie, 5×10-8). Some recent studies have moved beyond simply documenting that individuals with OCD are more likely to have a specific allele or candidate gene that other nonaffected individuals (ie, association studies) and have begun to explore the function of some of the genes being studied. Preliminary results suggest that may be a promising approach.85 However, none of these studies have yet been replicated, so it is too early to reach any definite conclusions.

Although specific regimens for corporal aspiration and irrigation

Although specific regimens for corporal aspiration and irrigation differ, one commonly used at our institution to treat an ischemic priapism is as follows: After a penile block is applied, a dilute solution of phenylephrine is prepared by adding 1 mL of phenylephrine

(10 mg/mL) to 99 mL of normal saline for a final concentration of 100 μg/mL. A 19-gauge butterfly needle is then inserted into the lateral aspect of one Inhibitors,research,lifescience,medical of the Ganetespib Phase 3 corpora cavernosa, and 1 or 2 mL of solution (ie, 100–200 μg of phenylephrine) is injected intracavernosally. If detumescence is not apparent within 2 minutes, an additional 1 or 2 mL of the phenylephrine solution is injected. This is repeated at 2-minute intervals until detumescence is achieved, with no more than 10 mL of total solution injected (ie, 1000 Inhibitors,research,lifescience,medical μg of phenylephrine). If detumescence does not occur with phenylephrine, the cavernosa should be irrigated with normal saline, with or without the addition of heparin. If there is difficulty aspirating the irrigate, a second 19-gauge butterfly needle can be placed on the opposite side of the Inhibitors,research,lifescience,medical shaft away from the first butterfly needle. To facilitate involvement of the entire cavernosa, 1 needle should be placed proximally with the contralateral needle placed distally. With regard to priapism that is secondary to an underlying systemic disorder, such as sickle cell disease and other hematologic malignancies, intracavernosal intervention should proceed concurrently

with systemic treatment. For example, for the patient in Case 1, data suggest that systemic measures alone (ie, hydration, oxygenation, blood exchange transfusions, analgesia, and alkalinization) have reduced efficacy when compared with concomitant systemic and cavernosal therapies.1 Surgical Interventions Distal shunts In the event that Inhibitors,research,lifescience,medical aspiration/irrigation with the use of a sympathomimetic

agent fails, additional surgical intervention may be required. The next step involves the creation of a shunt distally between the corpora cavernosa and the glans of the penis. The distinct venous drainage of the corpora spongiosum (and its distal continuation, the glans penis) and the corpora cavernosa allows Inhibitors,research,lifescience,medical the congested cavernosa to drain. A number of different types of shunts have been described, including the Ebbehøj, Winter’s, and Al-Ghorab. The Ebbehøj shunt involves insertion Batimastat of a scalpel through the glans penis lateral to the meatus into the underlying distal end of one or both of the rigid corpora cavernosa.13 The Winter’s shunt involves the same maneuver, however, with a large biopsy needle substituted for the scalpel.14 Finally, the Al-Ghorab shunt involves a transverse incision into the glans between the corona and superior aspect of the urethral meatus, with the incision carried down to excise the tunica albuginea off the tip of the corpora cavernosa.15 A summary of the efficacy and reported postintervention impotence as compiled by the AUA Guideline Panel is reported in Table 2.

Any difference between the deceased patients and survivors were c

Any difference between the deceased patients and survivors were computed with 95% confidence interval. A P value of ≤0.05 was considered statistically significant. Results As described in the methodology, patients’ records for a 5-month period were analyzed. Between July and November 2004, there were 11944 patients Bortezomib admitted to the RLUH among which 11372 (95%) patients were discharged alive and 572

(5%) patients died during hospitalization. The number of male and female patients were 6078 (51 %) and 5866 (49%), respectively. The age (mean±SD) of survivors was Inhibitors,research,lifescience,medical 56.0±22.0 and that for the deceased patients was 78.0±13.0 years. Eighty four percent of the patients were admitted to the medical wards, 1% to the ICU, and the rest (15%) were admitted to the regardless surgical wards. Deceased patients were significantly older than survivors (P<0.0001) and needed a longer hospitalization Inhibitors,research,lifescience,medical (19±24 vs. 8±16 days, P<0.0001) (table 1). Table 1 The characteristics of patients who had laboratory tests done in the first 24 hours of admission and the

wards to which they were admitted in the Royal Liverpool University Hospital between Inhibitors,research,lifescience,medical Jul-Nov 2004 Of 1650 (550 deceased cases and 1100 survivor controls) selected patients, 876 (53%) were males, 774 (47%) females, 42 (3%) admitted to ICU, and 1426 (86%) to medical, and 182 (11%) to surgical wards. The distribution of percentages of patients admitted to different wards of the hospital is shown in figure 1. Figure 1 The distribution (in percentage) of all patients (deceased and matched controls, n=1650) who admitted to various wards of Royal Liverpool Inhibitors,research,lifescience,medical University Hospital between July to November 2004 and had laboratory test done in the first 24 hours of their admission. … The median WBC count for the deceased and surviving patients was 11.4×109/l and 9.4×10 9/l, respectively (table 1), and there was a significantly difference between these groups (P=0.03). The number of patients with a WBC count of >10×109/l were 804, which comprised of 335 (42%) deceased cases and 469 (62%)

matched controls Inhibitors,research,lifescience,medical (table 2). Table 2 The frequencies of strata of WBC counts and age (in years) of deceased patients (n=550) and matching survivors (n=1100) The mean±SD age of AV-951 all selected patients (cases and matched controls, n=1650) was 61.0±22.0 years. There was a significant (P<0.0001) difference between the age of deceased patients (78.0±13.0 years) and matched survivors (53.0±21.0 years). Deceased patients had a significantly (P<0.001) longer hospitalization than the survivors (9 vs. 2 days, (table 2). The number of cases with leukocytosis (WBC counts >10×109/l) were significantly (P=0.0001) more in deceased patients (335 out of 550) than that in surviving patients (469 out of 1100). Moreover, the number of cases with leuckopenia (WBC counts <4×109/l) were significantly (P=0.002) more in deceased patients (14 out of 550) than that in surviving patients (12 out of 1100) (table 2).

The associated variants do not appear to have any obvious functio

The inhibitor Pazopanib associated variants do not appear to have any obvious function, and a thorough search for putative functional variants in all coding exons and across intron-exon boundaries revealed no obviously causal variant.64 Another positive GWAS finding in neuropsychiatry is with narcolepsy, a disorder that causes disrupted sleep patterns, with the patient often feeling excessively tired during the day, and

suffering sudden sleep attacks. PreGWAS studies had connected the disorder to an MHC class II antigen called HLA-DQB1*0602, and about 85% of narcoleptics carry this antigen.65 However, there remained unexplained heritability. Very recently, a GWAS study was done on 807 cases and 1074 controls, all positive for HLA-DQB1*0602. Inhibitors,research,lifescience,medical A significant association of three SNPs

in the T cell receptor alpha locus was found, which was then replicated in the same study in 1057 further cases and 1104 controls.66 Further selleck bio analysis showed a single SNP was responsible for the association, although it is not clear whether this variant is itself causal or how it may contribute Inhibitors,research,lifescience,medical to disease. This association is of particular interest because it adds considerable weight to the view that narcolepsy is an autoimmune disease, and as such, it would be the first autoimmune disease to be associated with a T-cell receptor locus. This finding also Inhibitors,research,lifescience,medical opens up the possibility of immunotherapy as a future treatment for narcolepsy. Other neuropsychiatric diseases for which definite, replicated effects of common SNPs have been found include schizophrenia, associated with MHC markers, NRGN and TCF4 Inhibitors,research,lifescience,medical (12 945 cases and 34 591 controls, ORs=1.24, 1.15,1.23),67,68 bipolar disorder, associated with ANK3 and CACNA1C (4 387 cases and 6 209 controls, ORs=1.45 and 1.18) 69, and autism, associated with SNPs at 5p14.1 (3 101 family members, 204 cases and 6 941 controls, OR=1.19).70,71 However, all of these were discovered with very large sample sizes and account for very little of the very high heritability of

these conditions. Rare variants Although studies of common variation in neuropsychiatric disease may be underwhelming, the opposite is true for Inhibitors,research,lifescience,medical rare variation. Although the SNP chips used for GWAS comprise only polymorphisms that are reasonably common (~≥5%), their data can be used Carfilzomib to find other types of non-SNP variants – specifically copy number variants (CNVs) – with much lower frequency. CNVs are duplications or deletions of large stretches of DNA – ranging in size from just a few hundred base pairs to many megabases. To detect such variants, the intensity data from the SNP chips is examined to determine whether particular stretches of SNPs are less intense than expected (or absent), which would indicate a deletion, or more intense than expected, which suggests a duplication.72 Because the CNVs are identified on an individual-by-individual basis, very rare CNVs, even those present in a single individual, can be found.

These differences hamper the populations these

These differences hamper the populations these criteria could be applied

for and the comparability of results. With respect to stringency of the criteria, data have shown that a realistic proportion of patients could fulfill the RSWG remission criteria and that more stringent criteria (eg, lower thresholds for the severity criteria of ≤2 or =1) are not realistic in clinical settings. The inclusion of an improvement criterion (eg, achievement of 50% reduction in BPRS total score from baseline), Inhibitors,research,lifescience,medical as applied in the criteria by Lieberman et al,8 increases the stringency and thereby the predictive validity for other outcome dimensions; however, only a minority of patients could reach such on outcome. Further, such a criterion implicates that studies including varying patient populations Inhibitors,research,lifescience,medical regarding baseline psychopathology are difficult (if not impossible) to compare. Applying less stringent severity criteria as proposed by Liberman et al11 (“moderately ill” or better) leads to higher

frequencies of patients in remission, but lowers Inhibitors,research,lifescience,medical the predictive validity for other outcome dimensions; further, its validity was hitherto insufficiently studied. Of note, the inclusion of other symptoms such as depression and suicidality in the set of remission items did not change the remission frequencies considerably. This result supports the conceptualization of the RSWG criteria, which used the most diagnostically specific items of the Positive and Negative Symptoms Scale (PANSS) to define remission.5 Items such as depression or Inhibitors,research,lifescience,medical anxiety relate to symptoms that are not diagnostic for schizophrenia. Conceptually, it may be subject of further discussion, whether depression and anxiety should be included in the RSWG criteria, as these dimensions were linked to poor quality of life. It may, however, be argued that these dimensions Inhibitors,research,lifescience,medical play a more import role in the broader concept of recovery. The applied 6-month

time criterion of the RSWG remission criteria is still a matter of debate. The only available study to date has found that a 3-month criterion has a comparable Brefeldin_A predictive validity for the stability of remission over time.13 Further, studies on early response and the proportion of patients with early response being in stable remission over time have shown that even shorter time periods are predictive for the stability of remission.62,63 Applying shorter time periods is additionally supported by the fact that approximately 75% of patients reaching the symptom severitycriteria threshold without fulfilling the 6-month time criterion remain in remission throughout a 6- to 60month follow-up period.

The content is solely the responsibility of the authors and does

The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies. Conflict of interest statement: The authors declare no conflicts of interest in preparing this article. Contributor Information Chadi A. Calarge, Associate Professor, Departments of Psychiatry and selleck chemical Carfilzomib Pediatrics, Inhibitors,research,lifescience,medical University of Iowa Carver College of Medicine, Psychiatry Research, 2-209 MEB, 500 Newton

Road, Iowa City, IA 52242, USA. Stephanie D. Ivins, University of Iowa Carver College of Medicine, Iowa City, IA, USA. Katherine J. Motyl, Maine Medical Center Research Institute, Scarborough, ME, USA. Amal A. Shibli-Rahhal, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA. Michael M. Bliziotes, Oregon Health and Science University, Portland, OR, USA. Janet A. Schlechte, Department of Internal Inhibitors,research,lifescience,medical Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA.
Borderline personality disorder (BPD) is characterized by chronic instability of Inhibitors,research,lifescience,medical affect and interpersonal relationships, and recurrent suicidal or self-injurious behavior.

BPD affects approximately 1–2% of the general population and up to 20% of psychiatric patients [Gunderson, 2008]. Approximately 1 in 10 individuals with BPD dies by suicide [Paris and Zweig-Frank, 2001]. Suicidal Inhibitors,research,lifescience,medical or self-injurious behaviors in individuals with BPD often result in recurrent, costly and prolonged hospitalizations. Clozapine decreases aggressive [Krakowski

et al. 2006] and self-injurious [Meltzer et al. 2003] behaviors in individuals with schizophrenia. Frankenburg and Zanarini reported improved functioning and reductions in aggressive and self-injurious behaviors in 15 individuals with BPD whom they treated with clozapine; moreover, these individuals chose to continue treatment with clozapine despite troubling side effects [Frankenburg and Zanarini, 1993]. Benedetti and colleagues noted reduced aggressive and self-injurious behaviors and Inhibitors,research,lifescience,medical improved functioning in 12 individuals with BPD treated with clozapine [Benedetti et al. 1998]. make it clear Chengappa and colleagues noted fewer incidents of self-mutilation and injuries against staff and peers, and decreased need for seclusion and restraint in seven chronically hospitalized women with severe BPD; four of the seven were released from the hospital and the remaining Entinostat three achieved higher levels of freedom in the hospital [Chengappa et al. 1999]. Parker was able to discharge seven out of eight chronically hospitalized self-injurious individuals with BPD after treating them with clozapine, saving Ohio more than US$36,000 per patient per year [Parker, 2002]. Numerous other case reports document comparable dramatic therapeutic benefits for similar severely ill individuals [Ferreri et al. 2004; Vohra, 2010; Swinton, 2001].

Another aspect of this bias is highlighted by the duration of use

Another aspect of this bias is highlighted by the duration of use results reporting that women who used HRT for more than 10 years had a stunning 45% lower mortality than non-users. This analysis as performed by the authors is flawed since the 10 years of use guarantees that a woman is still alive after 10 years, while non-users can die soon after cohort entry. In contrast,

the analysis of short-term use, which inherently has much less such guaranteed survival, found only a non-significant 5% lower mortality than non-users. The third example is the NHANES study of HRT and stroke, Inhibitors,research,lifescience,medical which involved a cohort of 1,910 women entering the study between 1971 and 1975, with long follow-up until 1987.44 There were 250 cases of stroke that occurred during the average 12 years of follow-up. To assess the effects of HRT, the authors used the HRT data collected at the first wave of follow-up of this cohort, namely during the period 1982–1984. After adjustment, the rate of stroke was 31% lower in HRT users (RR 0.69; 95% CI

0.47–1.00), while stroke mortality Inhibitors,research,lifescience,medical was 63% lower (RR 0.37; 95% CI 0.14–0.92). The authors concluded that HRT use is associated with a decrease in risk of stroke incidence and mortality in white postmenopausal women. Here again, we note that immortal time bias is introduced in this study by defining use of HRT, not at the baseline questionnaire, but by around Inhibitors,research,lifescience,medical 10 years later, at the first wave of follow-up. The women who replied to the 10-year follow-up questionnaire to indicate that they used HRT Inhibitors,research,lifescience,medical were necessarily alive at that time and therefore contributed a guaranteed survival of 10 years to the analysis. Finally, the fourth example involves a cohort of 2,436 women undergoing elective percutaneous transluminal coronary angioplasty (PTCA) between 1982 and 1994.45 Of Inhibitors,research,lifescience,medical these, the 137 postmenopausal women receiving HRT were matched with 200 postmenopausal

women not receiving HRT and followed up through 1995 (mean 5.5 years) for cardiovascular outcomes and death. The 7-year survival rate was 93% for the HRT users versus 75% for the non-users. The rate of cardiovascular death or myocardial infarction was 62% lower with HRT use (RR 0.38; 95% CI 0.19–0.79), with the conclusion that HRT use is associated with improved long-term outcomes after PTCA in postmenopausal women. In this study as well immortal time bias is introduced by defining use of HRT not only at the time of PTCA but also during AV-951 the follow-up period. Thus initiators of HRT during this follow-up are misclassified as exposed before they started HRT use, when they should have been classified as non-users up to that point, thus leading to immortal time bias. METFORMIN AND CANCER Metformin is a drug of choice for the Fluoro Sorafenib management of type 2 diabetes mellitus.46 It reduces insulin resistance and improves glycemic control and can be combined safely with other anti-diabetic drugs.

125 At the same time, sustained pressure and/or volume overload f

125 At the same time, sustained pressure and/or volume overload favour arrhythmogenesis. 25,124,126,127 Application of SAC-blockers such as GsMTx-4 has been shown to reversibly reduce the preload dependent increase in both incidence and duration of burst-pacing induced atrial fibrillation in isolated heart experiments. 28 In patients, Hedgehog Pathway it can be difficult to distinguish stretch-induced changes in electrophysiology

from other chronically occurring aspects of structural and functional remodelling. However, an impressive illustration of acute effects of ventricular loading has been provided by Waxman et al., 128 who showed that performing the Valsalva manoeuvre may terminate ventricular tachycardia by temporary reduction of ventricular filling. The Valsalva manoeuvre, an attempt to forcefully exhale against the closed glottis, increases intrathoracic pressure, favouring a net reduction of intravascular volume in the chest (i.e. impeding venous return and favouring arterial drainage to other parts of the body). In this study, the reduction in cardiac dimensions was confirmed radiographically. Cessation of ventricular

tachycardia coincided with removal of ventricular strain, while arrhythmia resumption occurred upon refilling after the end of the manoeuvre. Since this type of response can be seen not only in neurologically intact, but also in pharmacologically 128 or surgically 7 denervated patients (transplant recipients), it is not attributable to a nervous reflex. This highlights how removal of strain may unmask the presence of stretch-induced arrhythmias, even in a chronic setting. Various SAC have

been implicated in the heart’s (patho-)physiological responses to mechanical stimuli, but in the absence of firm identification of molecular substrates for cardiac SAC, successful mechanistic exploration of cardiac mechanosensitivity is a challenging task. Conceptually, it is pragmatic to subdivide SAC into two categories, SACNS and Cilengitide SACK. For both, there are several candidate proteins. SACNS were initially thought to be formed by TRP proteins and, most convincingly, TRPC6 antibodies inhibit whole-cell ISAC,NS in mouse ventricular myocytes. 58 However, subsequent heterologous expression studies yielded conflicting results. 50,56 More recently, attention has turned towards the newly discovered Piezo1 channels. 46 Although there is no published data yet on specific electrophysiological effects of Piezo1 in cardiomyocytes, comparative kinetic analysis suggests that these proteins may function as cardiac SACNS. In as far as cardiac SACK are concerned, recombinant TREK-1 has remarkably similar properties to endogenous SACK, 78 but the protein has yet to be identified in human heart.

The total neuropathologic burden, combined with depressed mood,

The total neuropathologic burden, combined with depressed mood,

lowers brain reserve capacity, leads to expression of MCI (eg, memory and executive dysfunction) earlier than otherwise would be the case, and, given the underlying neuropathology, progresses to AD along with co-occurring cerebrovascular disease; and (v) Individuals Inhibitors,research,lifescience,medical who develop cerebrovascular disease (with variable neuropathologic burden), that damages the frontostriatal circuitry, leading to late-life depression and MCI (eg, executive dysfunction),

that, will follow the course of the underlying cerebrovascular disease. Based on the weight of the findings in the published literature Inhibitors,research,lifescience,medical and consistent with our model depicted in Figure 1 , we suggest that Pathway #4 (Figure 2) leading to AD with co-occurring cerebrovascular disease is the most frequently occurring pathway among individuals with late-onset depression. Figure 2. Pathways Inhibitors,research,lifescience,medical linking depression to predominant cognitive outcomes. MCI, mild cognitive impairment; AD, Alzheimer’s disease; CVD, cerebrovascular disease. Understanding the pathways through Inhibitors,research,lifescience,medical which individuals with late-life depression develop progressive dementia in general, and AD in particular, is critical as novel treatment may Inhibitors,research,lifescience,medical prevent, selleck catalog forestall, or slow cognitive and/or disease progression. Selected abbreviations and acronyms AD Alzheimer’s disease CAD coronary

artery disease HPA hypothalamic-pituitary-adrenal MCI mild cognitive impairment MDE major depressive episode WMH hyperintense white matter regions Notes This work was supported in part by USPHS grants R01 MH072947, P50 AG05133, P50 Anacetrapib MH071944, R37/R01 MH43832 and T32MH19986. We would f like to thank several colleagues with whom we have discussed many of the topics discussed in this manuscript. These individuals at the University of Pittsburgh include Mary Ganguli, Ari Gildengers, Robert IMebes, Robert y Sweet and Ellen Whyte, and those at other universities include Rishi Bhalla, ‘ Gwenn Smith, David Steffens, Alan Thomas, George Alexopoulos, John O’ Brien, and Yvette Sheline.

Advances in artificial vision can achieve accuracies of several c

Advances in artificial vision can achieve accuracies of several centimeters at the expense of having to use an expensive infrastructure with a low modularity and high processing demand [6].Unlike these technologies, the ultrasound signal has several advantages such as a slow propagation speed, a negligible penetration in walls and a low cost of the transducers. The characteristics of the ultrasound signal are interesting for use in indoor ROCK1 positioning systems (IPS). The accuracy achieved by ultrasound is typically of a few centimeters. The time-of-flight (TOF) of the signal in its propagation from a transmitter device to a receiver device is used to calculate the distance between them taking into account the propagation speed of sound. This requires a correct temporal synchronization of the network nodes.The synchronization can be easily achieved through electrical pulses in systems with a wired connection between nodes. ATLINTIDA [7] is an example of this type of systems where the transmitter nodes (with fixed position) are wired to an interface through which they also receive power supply. The receipt of an electrical pulse in the transmitters indicates the beginning of signal transmission. On the other hand, the mobile node is battery operated. This node uses a radio module for transferring the received signal to an AD/DA card connected to a PC that calculates its position. The wired connection complicates the system installation and introduces additional costs in its deployment. This problem is solved using a wireless connection between nodes, although it entails others synchronization problems and requires to change the batteries regularly.The synchronization problem in wireless sensor networks (WSNs) is usually solved using radio frequency signals (RF). In the literature several examples of positioning systems based on ultrasound and RF can be found. The negligible propagation delay of the RF signal allows one to use this signal for beginning synchronously the transmission and reception processes of ultrasonic signal. Thus, achieving accurate distance estimations (inferred from the TOF of ultrasonic signal) is possible.For example, Active Bat [8] uses an infrastructure of fixed nodes (beacons) located on the ceiling that operate as ultrasound receivers. The target node (mobile) works as ultrasound emitter and its location is calculated from information of time-of-flight sent by the beacons to a central node. In this system a 433 MHz radio link for providing synchronization information to the network nodes is used. On the contrary, in Cricket system [9] the mobile node works as ultrasonic receiver and the beacons work as ultrasonic transmitters. The ultrasonic pulse transmission is accompanied by an RF pulse to provide the necessary synchronization.