11,624 research outputs found
The Potential For Managing Urban Canada Geese By Modifying Habitat
Urban Canada goose (Branta canadensis) populations have grown rapidly during the past three decades. This paper reviews short-term and long-term urban goose management techniques, and using data for the Twin Cities of Minnesota, assesses the potential utility of habitat modification. Ninety-four percent of Twin Cities damage complaints occurred during the brood-rearing period, 5% in fall, and \u3el% in spring and winter. The potential for reducing goose damage by altering nest habitat is insignificant, brood-rearing habitat high but expensive, and fall and winter habitat low and also costly. Fences effectively thwart flightless geese but can entrap birds leading to starvation. Cost projections for programs limiting the Twin Cities summer population at 25,000 were 325,000/year for processing for human consumption, 33.9 million for tall grass prairie, and $1.8 billion for ground juniper (Juniperus spp.). Human preference for savanna and the fear of urban crime associated with dense vegetation may hamper implementation of goose habitat modification
Consuming transgenic goats' milk containing the antimicrobial protein lysozyme helps resolve diarrhea in young pigs.
Childhood diarrhea is a significant problem in many developing countries and E. coli is a main causative agent of diarrhea in young children. Lysozyme is an antimicrobial protein highly expressed in human milk, but not ruminant milk, and is thought to help protect breastfeeding children against diarrheal diseases. We hypothesized that consumption of milk from transgenic goats which produce human lysozyme (hLZ-milk) in their milk would accelerate recovery from bacterial-induced diarrhea. Young pigs were used as a model for children and infected with enterotoxigenic E. coli. Once clinical signs of diarrhea developed, pigs were fed hLZ-milk or non-transgenic control goat milk three times a day for two days. Clinical observations and complete blood counts (CBC) were performed. Animals were euthanized and samples collected to assess differences in histology, cytokine expression and bacterial translocation into the mesenteric lymph node. Pigs consuming hLZ-milk recovered from clinical signs of infection faster than pigs consuming control milk, with significantly improved fecal consistency (p = 0.0190) and activity level (p = 0.0350). The CBC analysis showed circulating monocytes (p = 0.0413), neutrophils (p = 0.0219), and lymphocytes (p = 0.0222) returned faster to pre-infection proportions in hLZ-milk fed pigs, while control-fed pigs had significantly higher hematocrit (p = 0.027), indicating continuing dehydration. In the ileum, pigs fed hLZ-milk had significantly lower expression of pro-inflammatory cytokine IL-8 (p = 0.0271), longer intestinal villi (p<0.0001), deeper crypts (p = 0.0053), and a thinner lamina propria (p = 0.0004). These data demonstrate that consumption of hLZ-milk helped pigs recover from infection faster, making hLZ-milk an effective treatment of E. coli-induced diarrhea
Design Curves for Transient Heat Flow in Semiconductor Devices
We have ]performed a numerical simulation of heat flow in a cylindrical solid having a ,geometry typical of semiconductor devices. We present curves of temperature as a function of time, normalized to the thermal constants and the surface herat flux. These curves can be used in the design of serniconductor devices where transient or steady state temperature rise is a consideration
Accelerated Calvarial Healing in Mice Lacking Toll-Like Receptor 4
The bone and immune systems are closely interconnected. The immediate inflammatory response after fracture is known to trigger a healing cascade which plays an important role in bone repair. Toll-like receptor 4 (TLR4) is a member of a highly conserved receptor family and is a critical activator of the innate immune response after tissue injury. TLR4 signaling has been shown to regulate the systemic inflammatory response induced by exposed bone components during long-bone fracture. Here we tested the hypothesis that TLR4 activation affects the healing of calvarial defects. A 1.8 mm diameter calvarial defect was created in wild-type (WT) and TLR4 knockout (TLR4-/-) mice. Bone healing was tested using radiographic, histologic and gene expression analyses. Radiographic and histomorphometric analyses revealed that calvarial healing was accelerated in TLR4-/- mice. More bone was observed in TLR4-/- mice compared to WT mice at postoperative days 7 and 14, although comparable healing was achieved in both groups by day 21. Bone remodeling was detected in both groups on postoperative day 28. In TLR4-/- mice compared to WT mice, gene expression analysis revealed that higher expression levels of IL-1β, IL-6, TNF-α,TGF-β1, TGF-β3, PDGF and RANKL and lower expression level of RANK were detected at earlier time points (≤ postoperative 4 days); while higher expression levels of IL-1β and lower expression levels of VEGF, RANK, RANKL and OPG were detected at late time points (> postoperative 4 days). This study provides evidence of accelerated bone healing in TLR4-/- mice with earlier and higher expression of inflammatory cytokines and with increased osteoclastic activity. Further work is required to determine if this is due to inflammation driven by TLR4 activation. © 2012 Wang et al
Development of Process Technology for GaAs E/D MODFET Logic Circuits
The GaAs MODFET device is one of the prominent candidates for very high speed circuit applications. This thesis presents the MODFET DCFL inverter and other logic circuit design and process development. Working circuits of E/D type inverters, three input NAND and NOR logic gates and ring oscillators are reported
Investigation of a Resistive-Gate MESFET Contiguous Domain Oscillator
The goal of this research is to investigate a novel microwave oscillator — the MESFET version contiguous domain oscillator. By combining the transferred electron effect in GaAs material with the two dimensional electrostatics in the device, a series of contiguous electron packets can be generated in the channel of a resistive gate MESFET. Therefore this novel device can eliminate some restraints which are suffered by the presently existing oscillators, and provides unique new features for oscillators: a wide range of oscillation frequency (from a few tens of GHz to a hundred GHz), an ideal current source, instantaneous frequency tuning, compatibility with the presently existing planar semiconductor integration technology, etc. This investigation is composed of two parts. The first pa rt is to use various semiconductor processing technologies to fabricate the devices which can supply an ideal electrostatic condition for the electrons in the channel; the second part is the device characterization; which includes power output, frequency tunability, and the relationship between device performance and device parameters
What factors influence midwives to provide obstetric high dependency care on the delivery suite or request care be escalated away from the obstetric unit? Findings of a focus group study
Abstract Background In the United Kingdom, midwives will engage in discussions with the multidisciplinary team as to whether they can provide Obstetric High Dependency Care (OHDC) on the Delivery Suite or whether a woman’s care should be escalated to the critical care team. This study aimed to explore the question: What factors influence midwives to provide OHDC or request care be escalated away from the obstetric unit in hospitals remote from tertiary referral centres? Methods Focus groups were undertaken with midwives (n = 34) across three obstetric units in England, with annual birth rates ranging from 1500 to 5000 per annum, in District General Hospitals. Three scenarios in the form of video vignettes of handover were used as triggers for the focus groups. Scenario 1; severe pre-eclampsia, physiologically unstable 2; major postpartum haemorrhage requiring invasive monitoring 3; recent admission of woman with chest pain receiving facial oxygen and requiring continuous electrocardiogram (ECG) monitoring. Two focus groups were conducted in each of the obstetric units with experienced midwives. Data were analysed using a qualitative framework approach. Results Factors influencing midwives’ care escalation decisions included the care environment, a woman’s diagnosis and fetal or neonatal factors. The overall plan of care including the need for ECG and invasive monitoring were also influential factors. Midwives in the smallest obstetric unit did not have access to the facilities for OHDC provision. Midwives in the larger obstetric units provided OHDC but identified varying degrees of skill and sometimes used ‘workarounds’ to facilitate care provision. Midwifery staffing levels, skill mix and workload were also influential. Some differences of opinion were evident between midwives working in the same obstetric units as to whether OHDC could be provided and the support they would enlist to help them provide it. Reliance on clinical guidelines appeared variable. Conclusions Findings indicate that there may be inequitable OHDC provision at a local level. Organisationally robust systems are required to promote safe, equitable OHDC care including skills development for midwives and precise escalation guidelines to minimise workarounds. Training for midwives must include strategies that prevent skills fade. </jats:sec
Theory and Practice of Competition Advocacy at the FTC
This article was prepared as part of a recent symposium celebrating the Ninetieth Anniversary of the founding of the Federal Trade Commission. In addition, fall 2004 marks the Thirtieth Anniversary of a pivotal moment in the establishment of the modern advocacy program at the FTC, Chairman Lewis Engman’s speech on the economic burden that inefficient transportation regulation policies were imposing on the American economy. Although the FTC has been involved in advocacy activities since its founding, Engman’s speech symbolized a new aggressiveness on the part of the FTC in using its expertise to work with other governmental actors at all levels of the political system and in all branches of government to design policies that further competition and consumer choice.
Notwithstanding the beneficial impact that advocacy activities have had on the economy, the fortunes of the advocacy program have waxed and waned over time. In part, these mixed fortunes may reflect a lack of fundamental grounding of advocacy within the core mission of the FTC. The advocacy program, moreover, often has been politically controversial, exposing the Commission to criticism from special interests, Congress, and other governmental actors.
This article explores the theory and practice of competition advocacy, with the goal of explaining why the advocacy program should be recognized as a core element of the Commission’s mission. Advocacy can be used in conjunction with many of the FTC’s other tools, and in many situations the judicious use of advocacy can provide a low-cost and effective alternative to other enforcement options. The advocacy program is a unique and cost-effective tool for carrying out this mission. Because consumers are disadvantaged in the political arena vis-a-vis industry, they are likely to be unable to stop anticompetitive regulation on their own. Antitrust immunities, moreover, sometimes put anticompetitive regulation beyond the reach of traditional enforcement. By providing a means for the FTC to represent consumers’ interests directly in the policy-production mechanism, the advocacy program can overcome these two hurdles and provide protection for consumers at relatively low cost
Alternative Splicing of Four Trafficking Genes Regulates Myofiber Structure and Skeletal Muscle Physiology
During development, transcriptional and post-transcriptional networks are coordinately regulated to drive organ maturation. Alternative splicing contributes by producing temporal-specific protein isoforms. We previously found that genes undergoing splicing transitions during mouse postnatal heart development are enriched for vesicular trafficking and membrane dynamics functions. Here, we show that adult trafficking isoforms are also expressed in adult skeletal muscle and hypothesize that striated muscle utilizes alternative splicing to generate specific isoforms required for function of adult tissue. We deliver morpholinos into flexor digitorum brevis muscles in adult mice to redirect splicing of four trafficking genes to the fetal isoforms. The splicing switch results in multiple structural and functional defects, including transverse tubule (T-tubule) disruption and dihydropyridine receptor alpha (DHPR) and Ryr1 mislocalization, impairing excitation-contraction coupling, calcium handling, and force generation. The results demonstrate a previously unrecognized role for trafficking functions in adult muscle tissue homeostasis and a specific requirement for the adult splice variants
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