A Characterization of Serre Classes of Reflexive Modules Over a Complete Local Noetherian Ring

Serre classes of modules over a ring R are important because they describe relationships between certain classes of modules and sets of ideals of R. We characterize the Serre classes of three different types of modules. First we characterize all Serre classes of noetherian modules over a commutative noetherian ring. By relating noetherian modules to artinian modules via Matlis duality, we characterize the Serre classes of artinian modules. A module M is reflexive with respect to E if the natural evaluation map from M to its bidual is an isomorphism. When R is complete local and noetherian, take E as the injective envelope of the residue field of R. The main result provides a characterization of the Serre classes of reflexive modules over a complete local noetherian ring. This characterization depends on an ability to “construct” reflexive modules from noetherian modules and artinian modules. We find that Serre classes of reflexive modules over a complete local noetherian ring are in one-to-one correspondence with pairs of collections of prime ideals which are closed under specialization

DOWNSTREAM OIL DEREGULATION AND NIGERIAN ECONOMY

The Nigerian oil and gas industry has been experiencing a showdown since the announcement of the downstream oil deregulation policy. This paper, therefore, seeks to analyse the relationship between deregulation of the downstream sector and Nigerian economic performance using annual data from 1980 to 2009. The Ordinary Least Squares (OLS) regression method was employed to analyze the data. Chow Test was used to determine parameter stability of the regression model, while Granger Causality Test was used to predict the direction of influence. The findings reveal that increase in price of petroleum products and inflation rate were not as a result of deregulation, and deregulating price of petroleum products significantly influence economic growth with marginal inflation. The paper recommends that government should encourage private sector participation in the oil and gas industry

Fungal Endophytes from the Aerial Tissues of Important Tropical Forage Grasses \u3cem\u3e Brachiaria \u3c/em\u3e spp. in Kenya

Most, if not all plants in natural ecosystems are symbiotic with mycorrhizal fungi and/or fungal endophytes. This association between plant and fungi is believed to be over 400 million years old when plants first colonized the land (Redecker et al., 2000). These fungal symbionts play important roles on plant ecology, fitness, and evolution; shaping plant communities; and the community structure and diversity of associated organisms. The importance of fungal endophytes in cool season grasses production and effects of endophyte on the livestock health (Examples fescue toxicosis and ryegrass staggers) have been extensively investigated (Smith et al., 2009; di Menna et al., 2012). However, current understanding of fungal endophyte community of warm season grasses (including Brachiaria spp.) and the impact of these endophytes on livestock production is very limited. Therefore, this study aims to analyse fungal endophytes community inhabiting in the aerial tissues of important tropical grasses Brachiaria species from Kenya, an East African country representing place of origin for most of the Brachiaria species

PCR-based method for targeting 16S-23S rRNA intergenic spacer regions among Vibrio species

<p>Abstract</p> <p>Background</p> <p>The genus <it>Vibrio </it>is a diverse group of Gram-negative bacteria comprised of 74 species. Furthermore, the genus has and is expected to continue expanding with the addition of several new species annually. Consequently, it is of paramount importance to have a method which is able to reliably and efficiently differentiate the numerous <it>Vibrio </it>species.</p> <p>Results</p> <p>In this study, a novel and rapid polymerase chain reaction (PCR)-based intergenic spacer (IGS)-typing system for vibrios was developed that is based on the well-known IGS regions located between the 16S and 23S rRNA genes on the bacterial chromosome. The system was optimized to resolve heteroduplex formation as well as to take advantage of capillary gel electrophoresis technology such that reproducible analyses could be achieved in a rapid manner. System validation was achieved through testing of 69 archetypal <it>Vibrio </it>strains, representing 48 <it>Vibrio </it>species, from which an 'IGS-type' profile database was generated. These data, presented here in several cluster analyses, demonstrated successful differentiation of the 69 type strains showing that this PCR-based fingerprinting method easily discriminates bacterial strains at the species level among <it>Vibrio</it>. Furthermore, testing 36 strains each of <it>V. parahaemolyticus </it>and <it>V. vulnificus</it>, important food borne pathogens, isolated from a variety of geographical locations with the IGS-typing method demonstrated distinct IGS-typing patterns indicative of subspecies divergence in both populations making this technique equally useful for intraspecies differentiation, as well.</p> <p>Conclusion</p> <p>This rapid, reliable and efficient IGS-typing system, especially in combination with 16S rRNA gene sequencing, has the capacity to not only discern and identify vibrios at the species level but, in some cases, at the sub-species level, as well. This procedure is particularly well-suited for preliminary species identification and, lends itself nicely to epidemiological investigations providing information more quickly than other time-honoured methods traditionally used in these types of analyses.</p

Circuit-level theories for sensory dysfunction in autism: convergence across mouse models

Individuals with autism spectrum disorder (ASD) exhibit a diverse range of behavioral features and genetic backgrounds, but whether different genetic forms of autism involve convergent pathophysiology of brain function is unknown. Here, we analyze evidence for convergent deficits in neural circuit function across multiple transgenic mouse models of ASD. We focus on sensory areas of neocortex, where circuit differences may underlie atypical sensory processing, a central feature of autism. Many distinct circuit-level theories for ASD have been proposed, including increased excitation–inhibition (E–I) ratio and hyperexcitability, hypofunction of parvalbumin (PV) interneuron circuits, impaired homeostatic plasticity, degraded sensory coding, and others. We review these theories and assess the degree of convergence across ASD mouse models for each. Behaviorally, our analysis reveals that innate sensory detection behavior is heightened and sensory discrimination behavior is impaired across many ASD models. Neurophysiologically, PV hypofunction and increased E–I ratio are prevalent but only rarely generate hyperexcitability and excess spiking. Instead, sensory tuning and other aspects of neural coding are commonly degraded and may explain impaired discrimination behavior. Two distinct phenotypic clusters with opposing neural circuit signatures are evident across mouse models. Such clustering could suggest physiological subtypes of autism, which may facilitate the development of tailored therapeutic approaches

In situ permafrost thaw due to climate change drives holistic microbial community shifts with implications for methane cycling

Thawing permafrost is a potentially significant source of radiative forcing feedback due to increased emissions of methane, a biogenic greenhouse gas (GHG). This study investigated changes in the microbial community along a permafrost thaw gradient at Stordalen Mire, Sweden using 16S rRNA gene amplicon and metagenomic methods. In situ measurements of geochemical parameters, including CH4 and C isotopes, enabled linkage of community dynamics to significant shifts in C balance. The thaw gradient ranged from intact at a palsa (low productivity and GHG emissions), through partially thawed in a bog (high productivity, low GHG emissions) to a completely thawed fen (high productivity and GHG emissions). Microbial assemblages in both the palsa and fen were highly diverse (in both richness and evenness), consistent with climax communities. The microbial community in the bog had distinctly lower diversity, characteristic of ecosystem disturbance. The palsa community was dominated by Acidobacteria and Proteobacteria, as is typical of a range of soils including permafrost. Methanogens dominated both the bog and fen and were most abundant within the zone of water table fluctuation. Inferring methanogens’ production pathway from phylogeny showed a shift from mostly hydrogenotrophic methanogens in the bog towards acetotrophic methanogens in the fen. This corroborated porewater and flux emitted CH4 and CO2 carbon isotopic 13C signatures of CH4 and CO2. The fen, where the highest CH4 flux was recorded, was significantly richer in methanogenic archaea. A novel archaea, Candidatus Methanoflorens stordalenmirensis, was present at up to 70% relative abundance in the bog, enabling recovery of a population genome. The genome (and associated metaproteome) of ’M. stordalenmirensis’ indicates that hydrogenotrophic methane production is its main energy conservation pathway. ’Methanoflorens’ may be an indicator species of permafrost thaw, it is globally ubiquitous, and appears a major contributor to global methane production. Our results revealed a distinct difference in the microbial community structure and membership at each site, which can be directly associated with increasing methane emission and thaw state

Presynaptic Protein Synthesis Is Required for Long-Term Plasticity of GABA Release

Long-term changes of neurotransmitter release are critical for proper brain function. However, the molecular mechanisms underlying these changes are poorly understood. While protein synthesis is crucial for the consolidation of postsynaptic plasticity, whether and how protein synthesis regulates presynaptic plasticity in the mature mammalian brain remain unclear. Here, using paired whole-cell recordings in rodent hippocampal slices, we report that presynaptic protein synthesis is required for long-term, but not short-term, plasticity of GABA release from type 1 cannabinoid receptor (CB1)-expressing axons. This long-term depression of inhibitory transmission (iLTD) involves cap-dependent protein synthesis in presynaptic interneuron axons, but not somata. Translation is required during the induction, but not maintenance, of iLTD. Mechanistically, CB1 activation enhances protein synthesis via the mTOR pathway. Furthermore, using super-resolution STORM microscopy, we revealed eukaryotic ribosomes in CB1-expressing axon terminals. These findings suggest that presynaptic local protein synthesis controls neurotransmitter release during long-term plasticity in the mature mammalian brain

Design of a Transradial Myoelectric Prosthesis

Due to the rapid growth of children and the high cost of myoelectric technology, children are not given the same opportunities to use myoelectric prosthetics as adults. The Muscle Activated Prosthesis (MAP) team is developing an affordable, transradial, myoelectric prosthetic for a thirteen-year-old girl. The MAP team is designing a myoelectric prosthetic that will cost under $1,000, over 90% less than custom myoelectric devices on the market. This device has an EMG sensor, a microprocessor, a printed circuit board (PCB), linear actuator motors, and a battery organized within a 3D-printed transradial prosthesis to open and close the hand grip when the EMG detects electrical signals via muscle contractions in the client’s flexor carpi radialis. Currently, the team has fully assembled a prosthetic prototype and will obtain feedback from the partner, Ability Prosthetics, and the client to deliver a final prototype. This poster details the recent mechanical and electrical design optimizations, grip strength testing, and integration of mechanical and electrical components to build the current functioning prosthesis.https://mosaic.messiah.edu/engr2021/1009/thumbnail.jp

Muscle Activated 3D Printed Prosthetic Arm

Due to the rapid growth of children and the cost of myoelectric technology, children are not given the same opportunities to use myoelectric prosthetics as adults. The Muscle Activated Prosthesis (MAP) team seeks to reconcile this by creating an affordable, trans-radial, myoelectric prosthesis that utilizes the flexibility of 3D printing technology for a fourteen-year-old congenital amputee named Lily. The MAP team has completed the design and prototype of a myoelectric prosthesis with a material cost of approximately $1,000 as opposed to the$10,000-$20,000 cost of clinically accepted myoelectric prosthetic upper limbs. The 3D printed prosthetic arm prototype incorporates electromyography (EMG) electrodes, a motor and tendon system, an open-source prosthetic hand design, a custom printed circuit board (PCB), and lithium-ion battery power. The opening and closing of the prosthetic hand is controlled by the myoelectric signals from the user’s forearm contractions which can be tested by the team using our adaptive prosthetic attachment. All these components result in an affordable prosthetic that has the potential for customization and adaptation to different sized limbs. Funding for this work provided by The Collaboratory for Strategic Partnerships and Applied Research.https://mosaic.messiah.edu/engr2022/1009/thumbnail.jp

Vaccine coverage and factors associated with vaccine adherence in persons with HIV at an urban infectious disease clinic

Information on vaccination rates and factors associated with adherence in persons with HIV (PWH) is limited. We report vaccine adherence in 653 adult PWH attending an urban Infectious Disease Clinic from January 2015 to December 2021. Vaccines evaluated included influenza, pneumococcal, tetanus, hepatitis A virus (HAV) and hepatitis B virus (HBV), human papillomavirus (HPV), and zoster vaccines. Vaccine reminders were triggered at every visit, and all vaccines were accessible in the clinic. The mean age was 50 y (±SD 13), male gender was 78.6%, and black race was 74.3%. The overall adherence to all recommended vaccines was 63.6%. Vaccine adherence was \u3e90% for influenza, pneumococcal, and tetanus, \u3e80% for HAV and HBV, and ≥60% for HPV and zoster vaccines. The main predictor of adherence to all vaccines was ≥2 annual clinic visits (odds ratio [OR] 3.45; 95% confidence interval [CI] 2.36-5.05; p \u3c .001). Other predictors included an assigned primary care provider within the system (OR 2.89 [95% CI 1.71-5.00, p \u3c .001]) and CD4 \u3e200 cell/mm(3) at entry into care (OR 1.91 [95% CI 1.24-2.94, p = .0003]). Retention in care combined with vaccine reminders and accessibility of vaccines in the clinic can achieve high vaccine uptake in PWH