On the Cramer-Rao bound for carrier frequency estimation in the presence of phase noise

We consider the carrier frequency offset estimation in a digital burst-mode satellite transmission affected by phase noise. The corresponding Cramer-Rao lower bound is analyzed for linear modulations under a Wiener phase noise model and in the hypothesis of knowledge of the transmitted data. Even if we resort to a Monte Carlo average, from a computational point of view the evaluation of the Cramer-Rao bound is very hard. We introduce a simple but very accurate approximation that allows to carry out this task in a very easy way. As it will be shown, the presence of the phase noise produces a remarkable performance degradation of the frequency estimation accuracy. In addition, we provide asymptotic expressions of the Cramer-Rao bound, from which the effect of the phase noise and the dependence on the system parameters of the frequency offset estimation accuracy clearly result. Finally, as a by-product of our derivations and approximations, we derive a couple of estimators specifically tailored for the phase noise channel that will be compared with the classical Rife and Boorstyn algorithm, gaining in this way some important hints on the estimators to be used in this scenario

Risk-factor analysis for feline hyperthyroidism in the metropolitan area of Porto Alegre : a pilot case-control study

Background: Hyperthyroidism is the most common endocrinopathy in elderly cats and its prevalence varies greatly geographically. Since it was first described in 1979, it has shown a continuously increasing incidence. This fact has given rise to several hypothesis, and studies about the effects of endocrine disruptors on human and animal health are in full development. Aging, bisphenol-A and other endocrine disruptors present in the dust, were already documented as risk factors for feline hyperthyroidism. The aim of this study was to perform a risk analysis on the habits and lifestyle variables of domestic cats and their owners, and its possible relationship with feline hyperthyroidism. Materials, Methods and Results: Retrospective case-control epidemiological study. A 30-questions questionnaire was applied to owners of 28 hyperthyroid cats as well as to owners of 55 euthyroid cats aging more than eight-years (n:m) and living in the metropolitan area of Porto Alegre – RS. Criteria for hyperthyroidism diagnosis was assumed as compatible clinical presentation confirmed by elevated serum thyroxine concentration. Euthyroid control cats were selected by convenience from hospital medical records based on the absence of hyperthyroidism diagnosis and age. Univariate odds ratio (OR) and respective 95% confidence interval (95%CI) analysis was performed for each of the 22 variables surveyed. Exact Fischer´s test was performed to determine P-value, which was considered significant if P < 0.05. Student´s unpaired t-test was applied for age comparison between groups. Mean age of hyperthyroid cats was 13.2 ± 2.7 years (range: 7-18), while euthyroid cats mean age was 11.6 ± 2.4 years (range: 8-16) (P < 0.01). Higher exposure to canned foods was considered as a risk factor for hyperthyroidism in this population (OR = 2.87; 95% CI = 1.1 - 7.5; P = 0.032) as well as aging more than 12-years-old (OR = 3.14; 95% CI = 1.10 – 8.97; P = 0.048). Likewise, weekly or monthly bathing frequency represented a strong risk factor in those hyperthyroid cats studied (OR = 7.57; 95% CI = 1.41 - 40.55; P = 0.013). Regarding other items surveyed, such as the use of plastic accessories, contact with domestic dust, use of endoparasiticides, ectoparasiticides and vaccines, it was not possible to identify any association of these variables as risk or protective factors. Discussion: Even with a modest sample size, these results were in accordance with previous studies that analyzed hundreds of cats showing that advanced age, as well as the consumption of canned foods, are risk factors for the development of the disease. This study also raised the possibility of a risk factor related to frequent bathing. The explanation would be due to the possible presence of endocrine disruptors in cosmetic products used for bathing. This hypothesis needs further studies, since previous recommendations on hyperthyroidism preventive management suggests that bathing could have a protective effect since it cleans off the dust particles present in the fur. However, evidences that triclosan and parabens present in cosmetic products may act as thyroid endocrine disruptors have been recently raised. Further studies would be required to determine the effects of such inputs in felines’ health, since the etiopathogenesis of hyperthyroidism is uncertain and surely multifactorial. These genetic, environmental, and nutritional factors; should be analyzed together, as far as possible. Moreover, these findings are helpful to create preventive strategies against feline hyperthyroidism and corroborate with data previous published in epidemiological studies in other countries

Prevalência e fatores de risco para incontinência urinária em cadelas cinco anos após ovário histerectomia

Ovariohysterectomy (OHE) is the most performed elective surgery in veterinary medicine. Although this procedure brings benefits both to the animal and public health, acquired urinary incontinence is a possible complication resultant from it. The aim of this study was to determine the prevalence of urinary incontinence and evaluate size, breed, and time of surgery as risk factors in a population of spayed female dogs in the Hospital de Clínicas Veterinárias da Universidade Federal do Rio Grande do Sul, in the year of 2013, through the use of a multiple-choice screening instrument. Identified estimated prevalence was 11.27% and main risk factors were as follows: large size (OR = 7.12 IC95% = 1.42 – 35.67), Rottweiler breed (OR = 8.92; IC95% = 5.25 – 15.15), Pit-bull breed (OR = 4.14; IC95% = 2.19 – 7.83), and Labrador breed (OR = 2.73; IC95% = 1.53 – 4.87). Time of surgery was not considered a risk factor for urinary incontinence in this population (OR = 1.45; IC95% = 0.86 – 2.40). Even though most owners reported a small impact on their relationship with the animal, urinary incontinence hazard should be addressed before spaying.A ovário-histerectomia (OHE) é a cirurgia eletiva mais realizada em medicina veterinária. Embora seja um procedimento que beneficie a saúde pública e do animal, a incontinência urinária adquirida é uma complicação possível resultante desse procedimento. O objetivo deste estudo foi determinar a prevalência de incontinência urinária e avaliar porte, raça e momento da castração como fatores de risco em uma população de cadelas castradas no HCV/UFRGS, no ano de 2013, através do uso de um instrumento de triagem de múltipla escolha. A prevalência estimada foi de 11,27% e os principais fatores de risco foram: grande porte (OR = 7,12 IC95% = 1,42 - 35,67), raça Rottweiler (OR = 8,92; IC95% = 5,25 - 15,15), raça Pitbull (OR = 4,14; IC95% = 2,19 - 7,83) e raça Labrador (OR = 2,73; IC95% = 1,53 - 4,87). O tempo da cirurgia não foi considerado fator de risco para incontinência urinária nessa população (OR = 1,45; IC95% = 0,86 - 2,40). Embora a maioria dos proprietários tenha relatado um pequeno impacto no relacionamento com o animal, a possibilidade de incontinência urinária deve ser devidamente discutida antes da castração

Osmotic demyelination syndrome after primary hypoadrenocorticism crisis management

Background: Primary hypoadrenocorticism is a rare condition resulting from immune-mediated destruction of the adrenal cortices. It can also occur due to necrosis, neoplasms, infarctions, and granulomas. The clinical and laboratory changes are due to deficient secretion of glucocorticoids and mineralocorticoids, which leads to electrolyte disorders associated with hyponatremia and hyperkalemia. These disorders can cause hypotension, hypovolemia and shock, putting a patient’s life at risk if inadequate hydroelectrolytic supplementation and hormone replacement is provided. Nevertheless, rapid sodium chloride supplementation is contraindicated due to the risk of central pontine myelinolysis induction. The present study aims to describe a thalamic osmotic demyelination syndrome after management of a primary hypoadrenocorticism crisis in a 2-year-old, female West White Highland Terrier. Case: The patient had a presumptive diagnosis of hypoadrenocorticism already receiving oral prednisolone and gastrointestinal protectants in the last 2 days. After prednisolone dose reduction the dog presented a severe primary hypoadrenocorticism crisis treated with intravenous sodium chloride 0.9% solution along with supportive therapy. Four days after being discharged from the hospital, the patient showed severe neurological impairment and went back to the clinic where a neurological examination revealed mental depression, drowsiness, ambulatory tetraparesis and proprioceptive deficit of the 4 limbs, postural deficits, and cranial nerves with decreased response. Due to these clinical signs, a magnetic resonance imaging was performed. It showed 2 intra-axial circular lesions, symmetrically distributed in both thalamus sides, with approximately 0.8 cm in diameter each without any other anatomical changes on magnetic resonance imaging. The images were compatible with metabolic lesions, suggesting demyelination. Furthermore, liquor analysis did not show relevant abnormalities, except for a slight increase in density and pH at the upper limit of the reference range. After treatment, the patient had a good neurological evolution secondary to standard primary hypoadrenocorticism treatment, without sequelae. Discussion: In the present case report, primary hypoadrenocorticism gastrointestinal signs seemed to be triggered by a food indiscretion episode, not responsive to the symptomatic therapies employed. The patient´s breed and age (young West White Highland Terrier bitch) is in accordance with the demographic profile of patients affected by the disease, where young females are frequently more affected. Regarding the probable thalamic osmotic demyelination syndrome documented in this case, is important to notice that myelinolysis or demyelination is an exceedingly rare noninflammatory neurological disorder, initially called central pontine myelinolysis, which can occur after rapid correction of hyponatremia. It has already been observed in dogs after correction of hyponatremia of different origins, including hypoadrenocorticism and parasitic gastrointestinal disorders. Currently, the terms “osmotic myelinolysis” or “osmotic demyelination syndrome” are considered more suitable when compared to the term “central pontine myelinolysis” since it has been demonstrated in dogs and humans the occurrence of demyelination secondary to the rapid correction of hyponatremia in distinct regions of the central nervous system including pons, basal nuclei, striatum, thalamus, cortex, hypoppocampus, and cerebelum. The present case report emphasizes the difficulties for hormonal confirmation of primary hypoadrenocorticism in a patient already on corticosteroid treatment, as well as proposes that the current term osmotic demyelination syndrome replace the term “central pontine myelinolysis” in veterinary literature related to the management of hypoadrenocorticism crisis

First data on genetic diversity of the small pearl oyster Pinctada Radiata (Leach, 1814) in Mediterranean populations by means of the mitochondrial COX1 marker

This study gives a first molecular insight into the genetic structure of Pinctada radiata by analysing a mitochondrial DNA marker in four South -Central Mediterranean populations of this lessepsian bivalve. Specimens were collected from four central Mediterranean locations. Six polymorphic sites were found, defining seven haplotypes. Haplotype and nucleotide diversity values were low to moderate. The low levels of within -population genetic diversity detected in the present study are consistent with a scenario of founder effect, as expected for an invasive species. The shallow genetic structuring among the sampled populations may result from two factors – long larval duration which promotes the homogenization of the genetic pool through an effective gene flow or the current populations may not have had enough time to differentiate.peer-reviewe

Dual targeting of MDM2 and BCL2 as a therapeutic strategy in neuroblastoma

Wild-type p53 tumor suppressor activity in neuroblastoma tumors is hampered by increased MDM2 activity, making selective MDM2 antagonists an attractive therapeutic strategy for this childhood malignancy. Since monotherapy in cancer is generally not providing long-lasting clinical responses, we here aimed to identify small molecule drugs that synergize with idasanutlin (RG7388). To this purpose we evaluated 15 targeted drugs in combination with idasanutlin in three p53 wild type neuroblastoma cell lines and identified the BCL2 inhibitor venetoclax (ABT-199) as a promising interaction partner. The venetoclax/idasanutlin combination was consistently found to be highly synergistic in a diverse panel of neuroblastoma cell lines, including cells with high MCL1 expression levels. A more pronounced induction of apoptosis was found to underlie the synergistic interaction, as evidenced by caspase-3/7 and cleaved PARP measurements. Mice carrying orthotopic xenografts of neuroblastoma cells treated with both idasanutlin and venetoclax had drastically lower tumor weights than mice treated with either treatment alone. In conclusion, these data strongly support the further evaluation of dual BCL2/MDM2 targeting as a therapeutic strategy in neuroblastoma