Bee products in the prehistoric southern levant: evidence from the lipid organic record

Beehive products have a rich global history. In the wider Levantine region, bees had a significant role in Egypt and Mesopotamia, and intensive beekeeping was noted in Israel during the Biblical period when apiaries were first identified. This study investigates the origins of this extensive beekeeping through organic residue analysis of pottery from prehistoric sites in the southern Levant. The results suggest that beehive products from likely wild bees were used during the Chalcolithic period as a vessel surface treatment and/or as part of the diet. These functions are reinforced by comparison to the wider archaeological record. While the true frequency of beeswax use may be debated, alternatives to beehive products were seemingly preferred as wild resources contrasted with the socio-economic system centred on domesticated resources, controlled production and standardization. Bee products only became an important part of the economic canon in the southern Levant several millennia later.

Children should be offered vaccination against COVID-19

Since the start of the COVID-19 pandemic, there has been conflicting evidence on SARS-CoV-2 infection and transmission in children. Early studies reported only anecdotal outbreaks in school settings and low case numbers in children, driving speculation that the virus may not be as easily spread in this age group. However, these reports are unlikely to have represented the true frequency of infections, given the widespread school closures implemented to cut transmission opportunities and limitations of swab testing in children (lower uptake, swab volumes) resulting in missed cases. Indeed, subsequent studies measuring viral load in children reveal similar levels and trajectories as adults, indicating that children can readily transmit the virus and can accelerate infections throughout communities. In the midst of a fourth COVID-19 wave and a resurgence of cases in Canada, the majority with the highly transmissible and virulent B.1.617.2 (delta) variant, we discuss the pressing need for vaccination of children.

Modal frequencies of bridges from GNSS (GPS) monitoring data: Experimental, statistical evidence

GNSS technology (known especially for GPS satellites) for measurement of deflections has proved very efficient and useful in bridge structural monitoring, even for short stiff bridges, especially after the advent of 100 Hz GNSS sensors. Mode computation from dynamic deflections has been proposed as one of the applications of this technology. Apart from formal modal analyses with GNSS input, and from spectral analysis of controlled free attenuating oscillations, it has been argued that simple spectra of deflections can define more than one modal frequencies. To test this scenario, we analyzed 21 controlled excitation events from a certain bridge monitoring survey, focusing on lateral and vertical deflections, recorded both by GNSS and an accelerometer. These events contain a transient and a following oscillation, and they are preceded and followed by intervals of quiescence and ambient vibrations. Spectra for each event, for the lateral and the vertical axis of the bridge, and for and each instrument (GNSS, accelerometer) were computed, normalized to their maximum value, and printed one over the other, in order to produce a single composite spectrum for each of the four sets. In these four sets, there was also marked the true value of modal frequency, derived from free attenuating oscillations. It was found that for high SNR (signal-to-noise ratio) deflections, spectral peaks in both acceleration and displacement spectra differ by up to 0.3 Hz from the true value. For low SNR, defections spectra do not match the true frequency, but acceleration spectra provide a low-precision estimate of the true frequency. This is because various excitation effects (traffic, wind etc.) contribute with numerous peaks in a wide range of frequencies. Reliable estimates of modal frequencies can hence be derived from deflections spectra only if excitation frequencies (mostly traffic and wind) can be filtered along with most measurement noise, on the basis of additional data.

A Time-Shifting Algorithm for Alleviating Convergence Difficulties at Interior Acoustic Resonance Frequencies

This paper proposes a time-shifting boundary element method in the time domain to calculate the radiating pressures of an arbitrary object pulsating at eigenfrequencies of the interior (i.e., interior resonance frequencies). In this paper, the frequency shifting is time-step-dependent and could be viewed as an iterative, or relaxation, technique for the solution of the problem. The proposed method avoids numerical problems due to the internal resonance frequency by initializing the iteration with each scaled frequency. The scaled frequency is approximately equal to the true frequency at the last iterating time step. A sphere pulsating at the eigenfrequency in an infinite acoustic domain was calculated first; the result was compared with the analytical solution, and they were in good agreement. Moreover, two arbitrary-shaped radiators were taken as study cases to predict the radiating pressures at the interior resonance frequencies, and robustly convergent results were obtained. Finally, the accuracy of the proposed method was tested using a problem with a known solution. A point source was placed inside the object to compute the surface velocities; the computed surface pressures were identical to the pressures computed using the point source.

Epidemiology of pheochromocytoma and paraganglioma: population-based cohort study

Objective Despite the significant morbidity and mortality associated with pheochromocytoma and paraganglioma, little is known about their epidemiology. The primary objective was to determine the incidence of pheochromocytoma and paraganglioma in an ethnically diverse population. A secondary objective was to develop and validate algorithms for case detection using laboratory and administrative data. Design Population-based cohort study in Alberta, Canada from 2012 to 2019. Methods Patients with pheochromocytoma or paraganglioma were identified using linked administrative databases and clinical records. Annual incidence rates per 100 000 people were calculated and stratified according to age and sex. Algorithms to identify pheochromocytoma and paraganglioma, based on laboratory and administrative data, were evaluated. Results A total of 239 patients with pheochromocytoma or paraganglioma (collectively with 251 tumors) were identified from a population of 5 196 368 people over a period of 7 years. The overall incidence of pheochromocytoma or paraganglioma was 0.66 cases per 100 000 people per year. The frequency of pheochromocytoma and paraganglioma increased with age and was highest in individuals aged 60–79 years (8.85 and 14.68 cases per 100 000 people per year for males and females, respectively). An algorithm based on laboratory data (metanephrine >two-fold or normetanephrine >three-fold higher than the upper limit of normal) closely approximated the true frequency of pheochromocytoma and paraganglioma with an estimated incidence of 0.54 cases per 100 000 people per year. Conslusion The incidence of pheochromocytoma and paraganglioma in an unselected population of western Canada was unexpectedly higher than rates reported from other areas of the world.

Neurogenic Obesity-Induced Insulin Resistance and Type 2 Diabetes Mellitus in Chronic Spinal Cord Injury

The population with SCI is at a significant risk for both insulin resistance and type 2 diabetes mellitus (T2DM) secondary to neurogenic obesity. The prevalence of insulin resistance and T2DM in persons with SCI suggests that disorders of carbohydrate metabolism are at epidemic proportions within the population. However, the true frequency of such disorders may be underestimated because biomarkers of insulin resistance and T2DM used from the population without SCI remain nonspecific and may in fact fail to identify true cases that would benefit from intervention. Furthermore, diet and exercise have been used to help mitigate neurogenic obesity, but results on disorders of carbohydrate metabolism remain inconsistent, likely because of the various ways carbohydrate metabolism is assessed. The objective of this article is to review current literature on the prevalence and likely mechanisms driving insulin resistance and T2DM in persons with SCI. This article also explores the various assessments and diagnostic criteria used for insulin resistance and T2DM and briefly discusses the effects of exercise and/or diet to mitigate disorders of carbohydrate metabolism brought on by neurogenic obesity.

IgG reactivity profile to Paracoccidioides spp. antigens in people with asymptomatic Paracoccidioidomycosis

Introduction. Paracoccidioidomycosis (PCM) is a systemic mycosis caused by Paracoccidioides spp. As the disease is known to affect mostly men over 40 years old who previously worked handling soil, some cities of agricultural economy in endemic regions may have more cases of paracoccidioidal infection. Gap statement. The true frequency of PCM cannot be established in Brazil because it is not a disease of mandatory reporting. The detection of paracoccidioidal infection may assist in the planning of health services, in order to provide early detection of the disease and to prevent its worsening or even progression to death. In addition, little is described about sera reactivity with antigens from different species of Paracoccidiodes, especially P. lutzii. Aim. Current research was conducted in an inland municipality of southern Brazil, in order to assess infection rate within this endemic region of PCM disease. Methodology. ELISA was employed to evaluate 359 sera from random volunteers from Guarapuava, Paraná, Brazil, to detect IgG against cell-free antigens (CFA) from P. restrepiensis B339, P. americana LDR3 and P. lutzii LDR2. Confirmatory ELISA employed gp43 from B339. Reduction of cross-reactions was sought by treatment with sodium metaperiodate (SMP-CFA, SMP-gp43). Immunoblot was performed with 37 selected sera among those reactive in ELISA. Epidemiological profile was assessed by questionnaire. Results. ELISA reactivity was: CFA/SMP-CFA in general 37.3/17.8 %, B339 25.3/14.5 %, LDR3 24.5/1.4 %, LDR2 8.3/5.8 %; gp43/SMP-gp43 7.2/4.7 %. There were sera reactive with multiple CFAs. In immunoblot, five sera showed the same reaction profile with P. lutzii’s antigens as PCM disease sera. Rural residence and soil-related professions were risk factors for paracoccidioidal infection. Conclusion. The low prevalence is in accordance with previous reports of lower PCM disease endemicity in Guarapuava than in other areas of Paraná. Although P. brasiliensis seems to be the prevalent strain of the region, 21 sera from people who only lived in Guarapuava reacted with P. lutzii LDR2. CFA-ELISA with whole antigens seems a good option for serological screening in epidemiological surveys.

Competition for nutritional resources masks the true frequency of bacterial mutants

Background It is widely assumed that all mutant microorganisms present in a culture are able to grow and form colonies, provided that they express the features required for selection. Unlike wild-type Escherichia coli, PHO-constitutive mutants overexpress alkaline phosphatase and hence can hydrolyze glycerol-2-phosphate (G2P) to glycerol and form colonies on plates having G2P as the sole carbon source. These mutations mostly occur in the pst operon. However, the frequency of PHO-constitutive colonies on the G2P selective plate is exceptionally low. Results We show that the rate in which spontaneous PHO-constitutive mutations emerge is about 8.0 × 10−6/generation, a relatively high rate, but the growth of most existing mutants is inhibited by their neighboring wild-type cells. This inhibition is elicited only by non-mutant viable bacteria that can take up and metabolize glycerol formed by the mutants. Evidence indicates that the few mutants that do form colonies derive from microclusters of mutants on the selective plate. A mathematical model that describes the fate of the wild-type and mutant populations under these circumstances supports these results. Conclusion This scenario in which neither the wild-type nor the majority of the mutants are able to grow resembles an unavoidable “tragedy of the commons” case which results in the collapse of the majority of the population. Cooperation between rare adjacent mutants enables them to overcome the competition and eventually form mutant colonies. The inhibition of PHO-constitutive mutants provides an example of mutant frequency masked by orders of magnitude due to a competition between mutants and their ancestral wild-type cells. Similar “tragedy of the commons-like” cases may occur in other settings and should be taken into consideration while estimating true mutant frequencies and mutation rates.

A multi-method exploratory study of health professional students’ experiences with compliance behaviours

Background Research in healthcare, including students as participants, has begun to document experiences with negative compliance, specifically conformity and obedience. There is a growing body of experimental and survey literature, however, currently lacking is a direct measure of the frequency at which health professional students have negative experiences with conformity and obedience integrated with psychological factors, the outcomes of negative compliance, and students’ perceptions. Methods To develop empirical knowledge about the frequency of negative compliance and student perceptions during health professional education a multi-methods survey approach was used. The survey was administered to health professional students across ten disciplines at four institutions. Results The results indicated students regularly experience obedience and conformity and are influenced by impression management and displacement of responsibility. Moral distress was identified as a consistent negative outcome. Student self-reported experiences aligned with the empirical findings. Conclusions The findings of the present study demonstrate the pervasiveness of experiences with negative compliance during health professional’s education along with some attendant psychological factors. The findings have educational and practical implications, as well as pointing to the need for further integration of social and cognitive psychology in explaining compliance in healthcare. The results are likely generalizable to a population level however replication is encouraged to better understand the true frequency of negative compliance at a health professional population level.

A Multi-Method Exploratory Study of Health Professional Students’ Experiences with Compliance Behaviours

Background: Research in healthcare, including students as participants, has begun to document experiences with negative compliance, specifically conformity and obedience. There is a growing body of experimental and survey literature, however, currently lacking is a direct measure of the frequency at which health professional students have negative experiences with conformity and obedience integrated with psychological factors, the outcomes of negative compliance, and students’ perceptions. Methods: To develop empirical knowledge about the frequency of negative compliance and student perceptions during health professional education a multi-methods survey approach was used. The survey was administered to health professional students across ten disciplines at four institutions. Results: The results indicated students regularly experience obedience and conformity and are influenced by impression management and displacement of responsibility. Moral distress was identified as a consistent negative outcome. Student self-reported experiences aligned with the empirical findings. Conclusions: The findings of the present study demonstrate the pervasiveness of experiences with negative compliance during health professional’s education along with some attendant psychological factors. The findings have educational and practical implications, as well as pointing to the need for further integration of social and cognitive psychology in explaining compliance in healthcare. The results are likely generalizable to a population level however replication is encouraged to better understand the true frequency of negative compliance at a health professional population level.