Neurohormonal modulation of the Limulus heart: amine actions on neuromuscular transmission and cardiac muscle

The responses of Limulus cardiac neuromuscular junctions and cardiac muscle cells to four endogenous amines were determined in order to identify the cellular targets underlying amine modulation of heartbeat amplitude. The amines increased the amplitude of the Limulus heartbeat, with dopamine (DA) being more potent than octopamine, epinephrine or norepinephrine. The effect of DA on heartbeat amplitude was not blocked by phentolamine. DA enhanced the contractility of deganglionated heart muscle, with time course and dose-dependence similar to its effect on the intact heart. The amines also enhanced neuromuscular transmission, with time course and dose-dependence similar to their effects upon the intact heart. The amplitude of unitary excitatory junction potentials (EJPs) and frequency of miniature excitatory junction potentials (mEJPs) were increased by DA, while mEJP amplitude was unchanged. Thus DA, and probably the other amines, had a presynaptic effect. Combined actions upon cardiac muscle and cardiac neuromuscular transmission account for the ability of these amines to increase the amplitude of the Limulus heartbeat

A head-up display for mid-air drone recovery

During mid-air retrieval of parachute packages, the absence of a natural horizon creates serious difficulties for the pilot of the recovery helicopter. A head-up display (HUD) was tested in an attempt to solve this problem. Both a roll-stabilized HUD and a no-roll (pitch only) HUD were tested. The results show that fewer missed passes occurred with the roll-stabilized HUD when the horizon was obscured. The pilots also reported that the workload was greatly reduced. Roll-stabilization was required to prevent vertigo when flying in the absence of a natural horizon. Any HUD intended for mid-air retrieval should display pitch, roll, sideslip, airspeed, and vertical velocity

Storage and Search in Dynamic Peer-to-Peer Networks

We study robust and efficient distributed algorithms for searching, storing, and maintaining data in dynamic Peer-to-Peer (P2P) networks. P2P networks are highly dynamic networks that experience heavy node churn (i.e., nodes join and leave the network continuously over time). Our goal is to guarantee, despite high node churn rate, that a large number of nodes in the network can store, retrieve, and maintain a large number of data items. Our main contributions are fast randomized distributed algorithms that guarantee the above with high probability (whp) even under high adversarial churn: 1. A randomized distributed search algorithm that (whp) guarantees that searches from as many as $n - o(n)$ nodes ($n$ is the stable network size) succeed in ${O}(\log n)$-rounds despite ${O}(n/\log^{1+\delta} n)$ churn, for any small constant $\delta > 0$, per round. We assume that the churn is controlled by an oblivious adversary (that has complete knowledge and control of what nodes join and leave and at what time, but is oblivious to the random choices made by the algorithm). 2. A storage and maintenance algorithm that guarantees (whp) data items can be efficiently stored (with only $\Theta(\log{n})$ copies of each data item) and maintained in a dynamic P2P network with churn rate up to ${O}(n/\log^{1+\delta} n)$ per round. Our search algorithm together with our storage and maintenance algorithm guarantees that as many as $n - o(n)$ nodes can efficiently store, maintain, and search even under ${O}(n/\log^{1+\delta} n)$ churn per round. Our algorithms require only polylogarithmic in $n$ bits to be processed and sent (per round) by each node. To the best of our knowledge, our algorithms are the first-known, fully-distributed storage and search algorithms that provably work under highly dynamic settings (i.e., high churn rates per step).Comment: to appear at SPAA 201

Family Structure and Obesity Among U.S. Children

Child overweight and obesity in the U.S. is a significant public health issue. In 2008 nearly one-third of all U.S. children ages two to seventeen were obese or overweight [11]. For young children ages two to five, fully 21.2% were overweight (at or above the 85th%ile based on the CDCﾒs sex-specific BMI-for-age growth charts), while 10.4% of preschoolers were obese (at or above the 95th%ile) [11]. The prevalence of overweight and obesity among U.S. children has implications for children's future health and the health trajectory of the nation. For example, children who are overweight are more likely to grow up to be overweight or obese [1-3], to suffer health consequences both as children and later in life [4-6], and to experience social and behavioral difficulties [7,8]. Moreover, in 2009 the estimated annual healthcare costs in the U.S. related to obesity topped $145 billion [9], a figure which is expected to increase as obese children age and develop other health problems [10]. Thus, while recent data show that trends in childrenﾒs overweight and obesity rates are stabilizing, obesity continues to be a substantial problem, including among younger preschool-aged children, and identifying the contributing factors to it an important goal. By and large, scientists have identified nutrition and physical activity as the primary determinants of weight status for children [12]. Yet social factors have been shown to play an important role too. In examining this side of childrenﾒs weight development, parentsﾒ socioeconomic status has emerged as a primary social predictor. In particular, obesity in the U.S. is more prevalent among children who are racial or ethnic minorities [11,13], and whose parents have less income and lower levels of education [13]. Differences in parenting styles [14], culture [15], exposure to stressors [16,17], and neighborhood context [18] have been presented as some of the main mechanisms connecting parentsﾒ socioeconomic status with childrenﾒs risk of obesity. Going beyond this well-developed area of research, however, another social factor and indicator of family socioeconomic background that may be associated with childrenﾒs risk of obesity is family structure. Increasing family complexity over the past three decades in the United States means that more children are growing up in homes without two biological parents. Yet few studies have considered the role of different family structures in childrenﾒs weight status, and among those that have, even fewer have constructed and assessed categories for family structure that represent the diversity among U.S. families today

Marine fish landings in Kerala during 2016 - An overview

Kerala has 188 marine fish landing centres along the coastline of 590 km length and 1.2 lakh marine fishermen families. The estimated marine fish landings in Kerala during 2016 was 5,22,550 tonnes (t) contributing about 14% of the marine fish production in the countr

Prevalence of Sickle Cell Disease Among Anaemic Children Attending Mbeya Referral Hospital in Southern Tanzania

Background: Sickle cell disease (SCD) is a common genetic haematological disorder present in most countries in sub-Saharan Africa. In Tanzania, between 50% and 75% of the children born with SCD die before reaching the age of 5 years. The objective of this study was to determine the prevalence of SCD in children under 5 years of age attending Mbeya Referral Hospital between March and April 2014.   Methods: We conducted a hospital-based, cross-sectional, descriptive study in which 50 children under 5 were included at Mbeya Referral Hospital in southern Tanzania. Full blood counts were conducted using SYSMEX KX 21 and SYSMEX XT 2000i haematology analysers. The presence of haemoglobin S was determined using the sodium metabisulfite sickling test on blood samples with haemoglobin levels less than 10 g/dl.   Results: Blood samples from 50 infants and children under 5 were tested for sickle cell anaemia. Of these, 9 (18%) participants were found to be sickling test positive, 5 (55.6%) of whom were male and 4 (44.4%) were female. Almost half (n=4, 44.4%) of the SCD-positive children were between 25 and 36 months old, while the rest were between 13 and 24 months (n=2, 22.2%), 37 and 48 months (n=1, 11.1%), and 49 and 60 months (n=2, 22.2%) of age.   Conclusion: At our facility, among children under 5 with serum haemoglobin levels <10 g/dl, the prevalence of SCD was 18%. This might pose a substantial public health challenge in the region. More and larger studies are needed to help map out the sickle cell burden throughout the country to guide policy and management strategies

Enhancing Organizational Performance Through Effective Leadership in Public Enterprises: A Study of the Adamawa Investment and Property Development Company Ltd

The study examined the impact of effective leadership on the performance of public enterprises with a particular reference to the Adamawa Investment and Property Development Company Ltd. The study made use of content analysis and observation method. The study revealed that the performance of organization depends to a large extent on the efficiency or effectiveness of the leadership. It was also revealed that the Adamawa State Investment and Property Development Company Limited has not lived up to expectation due to leadership failure. The study made use of the transformational leadership theory. The theory believed in the leader’s ability to motivate the follower to accomplish more than what the followers planned to do by concentrating on the followers values and helping the followers align these values with the values of the organization. Based on the above, recommendations were given on the need for effective leadership if results must be achieved in an organization. Keywords: Leadership, organization, performance

Sorption of Phosphorus from Fertilizer Mixture

Studying phosphorus (P) sorption behavior is among the prerequisites for P management in the crop fields. The work presented in this chapter described P sorption data when fertilizer mixture (NH4NO3, KH2PO4, and KCl) was used to characterize sorption on soil. In addition to using fertilizer mixture, sorption experiments were also conducted using KH2PO4 prepared in 0.01 M KCl, 0.005 M CaCl2, and deionized water. The 24-h batch sorption experiments were conducted using a sandy soil to solution ratio of 1:2, and the equilibrium solution and sorbed data were described using Freundlich isotherm. Sorption kinetics experiments were conducted using times, 4, 8, 12, and 24 h. The Freundlich isotherm constant and sorbed P kinetics data for 0.005 M CaCl2 were significantly greater (p < 0.05) than for 0.01 M KCl and/or fertilizer mixture. The Freundlich isotherm constant and sorbed P kinetics data for deionized water were significantly lower (p < 0.05) than for 0.01 M KCl and/or fertilizer mixture. There was no significant difference in Freundlich isotherm constant and sorbed P kinetics data for 0.01 M KCl and fertilizer mixture. The sorption data showed the importance of using the fertilizer mix applied to the field when conducting sorption experiments

Scaling up HIV self-testing in sub-Saharan Africa: a review of technology, policy and evidence.

PURPOSE OF REVIEW: HIV self-testing (HIVST) can provide complementary coverage to existing HIV testing services and improve knowledge of status among HIV-infected individuals. This review summarizes the current technology, policy and evidence landscape in sub-Saharan Africa and priorities within a rapidly evolving field. RECENT FINDINGS: HIVST is moving towards scaled implementation, with the release of WHO guidelines, WHO prequalification of the first HIVST product, price reductions of HIVST products and a growing product pipeline. Multicountry evidence from southern and eastern Africa confirms high feasibility, acceptability and accuracy across many delivery models and populations, with minimal harms. Evidence on the effectiveness of HIVST on increased testing coverage is strong, while evidence on demand generation for follow-on HIV prevention and treatment services and cost-effective delivery is emerging. Despite these developments, HIVST delivery remains limited outside of pilot implementation. SUMMARY: Important technology gaps include increasing availability of more sensitive HIVST products in low and middle-income countries. Regulatory and postmarket surveillance systems for HIVST also require further development. Randomized trials evaluating the effectiveness and cost-effectiveness under multiple distribution models, including unrestricted delivery and with a focus on linkage to HIV prevention and treatment, remain priorities. Diversification of studies from west and central Africa and around blood-based products should be addressed