The effects of a chemosterilant (Mestranol) on population and behavior in the Richardson's ground squirrel (Spermophilus richardsonii) in Alberta

A chemosterilant, mestranol, was administered to three populations of Richardson's ground squirrel in southeastern Alberta. Mestranol was given to all squirrels in one plot, to only 50 percent in another plot, while a third plot remained as control. In all plots social behavior and population dynamics were followed over two seasons by live trapping and visual observations. Mestranol sterilized all females who received the drug shortly before or in early pregnancy; accordingly the birth rates were reduced. Levels of total aggression were also reduced but increased survival and immigration rates nullified the effects of the treatment during the first season. During the second season, low birth rates due to repeated treatment in one plot and to adult emigration and unknown causes in the other, were not compensated for by immigration. As a result of the repeated mestranol treatment and in one case also of adult emigration, the numbers of squirrels were reduced in the vicinity, thus limiting potential immigration in the treated plots. As a consequence, both treated populations crashed, demonstrating the effectiveness of mestranol

Efficacy of Vitaflo 280 to control soil- and seed-borne diseases of pea and lentil, and compatibility with rhizobium inoculants

Non-Peer ReviewedLentil (Lens culinaris Medikus) and pea (Pisum sativum L.) have the ability to fix dinitrogen (N2) from the atmosphere. Rhizobium inoculants are applied to the seed to ensure effective N2 fixation. In addition, fungicidal seed treatments are recommended to control extremely aggressive diseases such as Ascochyta, Botrytis, Fusarium, and Rhizoctonia seedling blight. To determine the efficacy of Vitaflo 280 to control seedling blight of pea and lentil caused by Botrytis cinerea, Mycosphaerella pinodes (Ascochyta blight), Rhizoctonia solani and Fusarium spp. experiments were established at several locations and years in western Canada. To determine the effect of Crown, Allegiance FL, Vitaflo 280, and Apron Maxx on the ability of Rhizobium inoculants to nodulate and fix N2 from the atmosphere experiments were established at two locations in Saskatchewan in 2002. Vitaflo 280 at the recommended rates effectively controls seedling blight of lentil caused by seed-borne Botrytis cinerea and soil-borne Fusarium spp and Rhizoctonia solani. Vitaflo 280 at the recommended rates effectively controls seedling blight of pea caused by seed-borne Mycosphaerella pinodes and soil-borne Fusarium spp and Rhizoctonia solani. In addition, Allegiance FL, Crown, Vitaflo 280, and Apron Maxx at the recommended rates have no effect on visual nodulation or the ability of the Rhizobium to fix N2 from the atmosphere

Effects of Crown (carbathiin and thiabendazole), Allegiance FL (metalaxyl), Vitaflo 280 (carbathiin and thiram), and Apron Maxx (fluodioxonil and metalaxyl) on N2 fixation of chickpea, dry bean, lentil, and pea

Non-Peer Reviewe

Genetic Inhibition of Phosphorylation of the Translation Initiation Factor eIF2alpha Does Not Block Abeta-Dependent Elevation of BACE1 and APP Levels or Reduce Amyloid Pathology in a Mouse Model of Alzheimer's Disease

beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) initiates the production of beta-amyloid (Abeta), the major constituent of amyloid plaques in Alzheimer's disease (AD). BACE1 is elevated approximately 2-3 fold in AD brain and is concentrated in dystrophic neurites near plaques, suggesting BACE1 elevation is Abeta-dependent. Previously, we showed that phosphorylation of the translation initiation factor eIF2alpha de-represses translation of BACE1 mRNA following stress such as energy deprivation. We hypothesized that stress induced by Abeta might increase BACE1 levels by the same translational mechanism involving eIF2alpha phosphorylation. To test this hypothesis, we used three different genetic strategies to determine the effects of reducing eIF2alpha phosphorylation on Abeta-dependent BACE1 elevation in vitro and in vivo: 1) a two-vector adeno-associated virus (AAV) system to express constitutively active GADD34, the regulatory subunit of PP1c eIF2alpha phosphatase; 2) a non-phosphorylatable eIF2alpha S51A knockin mutation; 3) a BACE1-YFP transgene lacking the BACE1 mRNA 5' untranslated region (UTR) required for eIF2alpha translational regulation. The first two strategies were used in primary neurons and 5XFAD transgenic mice, while the third strategy was employed only in 5XFAD mice. Despite very effective reduction of eIF2alpha phosphorylation in both primary neurons and 5XFAD brains, or elimination of eIF2alpha-mediated regulation of BACE1-YFP mRNA translation in 5XFAD brains, Abeta-dependent BACE1 elevation was not decreased. Additionally, robust inhibition of eIF2alpha phosphorylation did not block Abeta-dependent APP elevation in primary neurons, nor did it reduce amyloid pathology in 5XFAD mice. We conclude that amyloid-associated BACE1 elevation is not caused by translational de-repression via eIF2alpha phosphorylation, but instead appears to involve a post-translational mechanism. These definitive genetic results exclude a role for eIF2alpha phosphorylation in Abeta-dependent BACE1 and APP elevation. We suggest a vicious pathogenic cycle wherein Abeta42 toxicity induces peri-plaque BACE1 and APP accumulation in dystrophic neurites leading to exacerbated Abeta production and plaque progression

Proximity Effects and Nonequilibrium Superconductivity in Transition-Edge Sensors

We have recently shown that normal-metal/superconductor (N/S) bilayer TESs (superconducting Transition-Edge Sensors) exhibit weak-link behavior.1 Here we extend our understanding to include TESs with added noise-mitigating normal-metal structures (N structures). We find TESs with added Au structures also exhibit weak-link behavior as evidenced by exponential temperature dependence of the critical current and Josephson-like oscillations of the critical current with applied magnetic field. We explain our results in terms of an effect converse to the longitudinal proximity effect (LoPE)1, the lateral inverse proximity effect (LaiPE), for which the order parameter in the N/S bilayer is reduced due to the neighboring N structures. Resistance and critical current measurements are presented as a function of temperature and magnetic field taken on square Mo/Au bilayer TESs with lengths ranging from 8 to 130 {\mu}m with and without added N structures. We observe the inverse proximity effect on the bilayer over in-plane distances many tens of microns and find the transition shifts to lower temperatures scale approximately as the inverse square of the in- plane N-structure separation distance, without appreciable broadening of the transition width. We also present evidence for nonequilbrium superconductivity and estimate a quasiparticle lifetime of 1.8 \times 10-10 s for the bilayer. The LoPE model is also used to explain the increased conductivity at temperatures above the bilayer's steep resistive transition.Comment: 10 pages, 8 figure

Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors

We have found experimentally that the critical current of a square superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T. As a consequence, the effective transition temperature T(sub c) of the TES is current-dependent and at fixed current scales as 1/L(sup 2). We also have found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. The observed behavior has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. We have observed the proximity effect in these devices over extraordinarily long lengths exceeding 100 microns

Multiabsorber Transition-Edge Sensors for X-Ray Astronomy

We are developing arrays of position-sensitive microcalorimeters for future x-ray astronomy applications. These position-sensitive devices commonly referred to as hydras consist of multiple x-ray absorbers, each with a different thermal coupling to a single-transition-edge sensor microcalorimeter. Their development is motivated by a desire to achieve very large pixel arrays with some modest compromise in performance. We report on the design, optimization, and first results from devices with small pitch pixels (<75 m) being developed for a high-angular and energy resolution imaging spectrometer for Lynx. The Lynx x-ray space telescope is a flagship mission concept under study for the National Academy of Science 2020 decadal survey. Broadband full-width-half-maximum (FWHM) resolution measurements on a 9-pixel hydra have demonstrated E(FWHM) = 2.23 0.14 eV at Al-K, E(FWHM) = 2.44 0.29 eV at Mn-K, and E(FWHM) = 3.39 0.23 eV at Cu-K. Position discrimination is demonstrated to energies below <1 keV and the device performance is well-described by a finite-element model. Results from a prototype 20-pixel hydra with absorbers on a 50-m pitch have shown E(FWHM) = 3.38 0.20 eV at Cr-K1. We are now optimizing designs specifically for Lynx and extending the number of absorbers up to 25/hydra. Numerical simulation suggests optimized designs could achieve 3 eV while being compatible with the bandwidth requirements of the state-of-the art multiplexed readout schemes, thus making a 100,000 pixel microcalorimeter instrument a realistic goal

A systematic review and meta-analysis of 271 PCDH19-variant individuals identifies psychiatric comorbidities, and association of seizure onset and disease severity

Epilepsy and Mental Retardation Limited to Females (EFMR) is an infantile onset disorder characterized by clusters of seizures. EFMR is due to mutations in the X-chromosome gene PCDH19, and is underpinned by cellular mosaicism due to X-chromosome inactivation in females or somatic mutation in males. This review characterizes the neuropsychiatric profile of this disorder and examines the association of clinical and molecular factors with neuropsychiatric outcomes. Data were extracted from 38 peer-reviewed original articles including 271 individual cases. We found that seizure onset ≤12 months was significantly associated (p = 4.127 × 10⁻⁷) with more severe intellectual disability, compared with onset >12 months. We identified two recurrent variants p.Asn340Ser and p.Tyr366Leufs*10 occurring in 25 (20 unrelated) and 30 (11 unrelated) cases, respectively. PCDH19 mutations were associated with psychiatric comorbidities in approximately 60% of females, 80% of affected mosaic males, and reported in nine hemizygous males. Hyperactive, autistic, and obsessive-compulsive features were most frequently reported. There were no genotype-phenotype associations in the individuals with recurrent variants or the group overall. Age at seizure onset can be used to provide more informative prognostic counseling.Kristy L Kolc, Lynette G Sadleir, Ingrid E Scheffer, Atma Ivancevic, Rachel Roberts, Duyen H Pham, Jozef Gec