2,239 research outputs found
The effects of lithium on reticulo-rumen motility of sheep and goats
Lithium salts are used experimentally to induce food aversions and as a marker for measuring the intake of supplements (Ralphs, 1992)
A SWEET solution to rice blight
Bacterial blight is an important disease of rice that is particularly destructive in Southeast Asia and sub-Saharan Africa, exacerbated by the heavy rains of the monsoon seasons. Estimated crop loss due to bacterial blight may be as high as 75%, with millions of hectares of rice affected annually. In this issue, an international team of researchers describes the use of CRISPR editing to generate rice plants that are broadly resistant to the main pathogen that causes rice blight, Xanthomonas oryzae pv. oryzae (Xoo)1. To enhance the durability and
management of resistance, the team has also developed a kit to trace the disease, and its virulence and resistance alleles2
Geographic patterns of phenotypic diversity in sorghum (Sorghum bicolor (L.) Moench) landraces from North Eastern Ethiopia
Understanding the pattern of genetic variability is an important component of germplasm collection and
conservation as well as the cropâs improvement process including the selection of parents for making
new genetic recombination. Nine hundred seventy four sorghum landraces from North Eastern (NE)
Ethiopia were evaluated for agro-morphologic characters to assess geographic patterns of phenotypic
diversity and to identify whether there are specific areas of high diversity for particular traits. The
Shannon-Weaver diversity index (Hâ˛) for qualitative traits ranged from 0.30 to 0.93 (mean = 0.67) for
grain covering and grain color, respectively. The landraces also displayed highly significant differences
(p<0.01) for all the quantitative traits with days to flowering ranging from 64 to 157 days (range = 93),
days to maturity from 118 to 215 (range=97) days, plant height from 115 to 478 cm; 1000-seeds weight
from 18 to 73 g, and grain number from 362 to 9623. The first five principal component axes captured
71% of the total variation with days to flowering and maturity, leaf number and length, panicle weight,
grain weight and number per panicle, panicle length, length of primary branches, 1000-seeds weight
and internode length accounting for most of the variability. Cluster analysis grouped the landraces into
ten clusters. The clustering of zones and districts revealed close relationship between geographic
locations based on proximities and agro-ecological similarities. Differentiation analysis showed that
most of the landraces variability was within rather than between geographic origins of the landraces,
indicating weak genetic differentiation among landraces from predefined geographic origins such as
political administrative zones and districts. The weak differentiation might be due to frequent gene flow
across the study area because of seed exchanges among farmers
Emission Line Galaxies in the STIS Parallel Survey I: Observations and Data Analysis
In the first three years of operation STIS obtained slitless spectra of
approximately 2500 fields in parallel to prime HST observations as part of the
STIS Parallel Survey (SPS). The archive contains almost 300 fields at high
galactic latitude (|b|>30) with spectroscopic exposure times greater than 3000
seconds. This sample contains 220 fields (excluding special regions and
requiring a consistent grating angle) observed between 6 June 1997 and 21
September 2000, with a total survey area of about 160 square arcminutes. At
this depth, the SPS detects an average of one emission line galaxy per three
fields. We present the analysis of these data, and the identification of 131
low to intermediate redshift galaxies detected by optical emission lines. The
sample contains 78 objects with emission lines that we infer to be redshifted
[OII]3727 emission at 0.43<z<1.7. The comoving number density of these objects
is comparable to that of H-alpha emitting galaxies in the NICMOS parallel
observations. One quasar and three probable Seyfert galaxies are detected. Many
of the emission-line objects show morphologies suggestive of mergers or
interactions. The reduced data are available upon request from the authors.Comment: 58 preprint pages, including 26 figures; accepted for publication in
ApJ
DNA markers reveal genetic structure and localized diversity of Ethiopian sorghum landraces
North Eastern Ethiopia is a major sorghum-growing region. A total of 415 sorghum landraces were sampled to represent the range of agro-ecologies (three altitude ranges) as well as spatial heterogeneity, that is, 4 zones: North Welo, South Welo, Oromiya and North Shewa with each zone containing 2 to 5 districts. The landraces were genotyped with simple sequence repeats (SSR) and inter simple sequence repeats (ISSR) markers. High genetic diversity was observed among the landraces for both marker systems. STRUCTURE analysis revealed 4 clusters of genetically differentiated groups of landraces. Cluster analysis revealed a close relationship between landraces along geographic proximity with genetic distance between landraces increasing with an increase in geographic distance. The grouping of landraces based on districts was influenced by clinal trend and geographic proximity. The FST statistics showed significant geographic differentiation among landraces at various levels of predefined geographic origin but a large portion of the variation was among landraces within rather than between predefined populations. The landraces from North Shewa were predominantly in one cluster, and landraces from this area also exhibited the greatest allelic diversity and the highest number of private alleles. There was low variation among the highland Zengada landraces, but these landraces were quite strongly differentiated and fell into one population cluster. The low to moderate genetic differentiation between landraces from various geographic origins could be attributed to gene flow across the region as a consequence of seed exchange among farmers
Can we bridge the gap? Knowledge and practices related to Diabetes Mellitus among general practitioners in a developing country: A cross sectional study
<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus is becoming a serious public health problem in Sri Lanka and many other developing countries in the region. It is well known that effective management of diabetes reduces the incidence and progression of many diabetes related complications, thus it is important that General Practitioners (GPs) have sound knowledge and positive attitudes towards all aspects of its management. This study aims to assess knowledge, awareness and practices relating to management of Diabetes Mellitus among Sri Lankan GPs.</p> <p>Methods</p> <p>A cross-sectional study was conducted among all 246 GPs registered with the Ceylon College of General Practitioners using a pre-validated self-administered questionnaire.</p> <p>Results</p> <p>205 responded to the questionnaire(response rate 83.3%). Their mean duration of practice was 28.7 Âą 11.2 years. On average, each GP had 27 Âą 25 diabetic-patient consultations per-week. 96% managed diabetic patients and 24% invariably sought specialist opinion. 99.2% used blood glucose to diagnose diabetes but correct diagnostic cut-off values were known by only 48.8%. Appropriate use of HbA1c and urine microalbumin was known by 15.2% and 39.2% respectively. 84% used HbA1c to monitor glyceamic control, while 90.4% relied on fasting blood glucose to monitor glyceamic control. Knowledge on target control levels was poor.</p> <p>Nearly 90% correctly selected the oral hypoglyceamic treatment for obese as well as thin type 2 diabetic patients. Knowledge on the management of diabetes in pregnancy was poor. Only 23.2% knew the correct threshold for starting lipid-lowering therapy. The concept of strict glycaemic control in preference to symptom control was appreciated only by 68%. The skills for comprehensive care in subjects with multiple risk factors were unsatisfactory.</p> <p>Conclusions</p> <p>The study was done among experienced members of the only professional college dedicated to the specialty. However, we found that there is room for improvement in their knowledge and practices related to diabetes. We recommend continuing medical education and training programs to update GP's knowledge in order to improve health outcomes in this group of patients.</p
New Insights Into the Anticonvulsant Effects of Essential Oil From Melissa officinalis L. (Lemon Balm)
Melissa officinalis L. is used in traditional European and Iranian folk medicines to treat a plethora of neurological diseases including epilepsy. We utilized the in vitro and in vivo models of epilepsy to probe the anticonvulsant potentials of essential oil from M. officinalis (MO) to gain insight into the scientific basis for its applications in traditional medicine for the management of convulsive disorders. MO was evaluated for effects on maximal electroshock (MES) and pentylenetetrazole (PTZ) -induced seizures in mice, on 4âaminopyridine (4-AP)-brain slice model of epilepsy and sustained repetitive firing of current clamped neurons; and its ameliorative effects were examined on seizure severity, anxiety, depression, cognitive dysfunction, oxidative stress and neuronal cell loss in PTZ-kindled rats. MO reversibly blocked spontaneous ictal-like discharges in the 4-AP-brain slice model of epilepsy and secondary spikes from sustained repetitive firing, suggesting anticonvulsant effects and voltage-gated sodium channel blockade. MO protected mice from PTZâ and MESâinduced seizures and mortality, and ameliorated seizure severity, fear-avoidance, depressive-like behavior, cognitive deficits, oxidative stress and neuronal cell loss in PTZâkindled rats. The findings warrant further study for the potential use of MO and/or its constituent(s) as adjunctive therapy for epileptic patients
Genomic interventions for sustainable agriculture
Agricultural production faces a Herculean challenge to feed the increasing global population.
Food production systems need to deliver more with finite land and water resources while
exerting the least negative influence on the ecosystem. The unpredictability of climate change
and consequent changes in pests/pathogens dynamics aggravate the enormity of the challenge.
Crop improvement has made significant contributions towards food security, and breeding
climate-smart cultivars are considered the most sustainable way to accelerate food production.
However, a fundamental change is needed in the conventional breeding framework in order to
respond adequately to the growing food demands. Progress in genomics has provided new
concepts and tools that hold promise to make plant breeding procedures more precise and
efficient. For instance, reference genome assemblies in combination with germplasm sequencing
delineate breeding targets that could contribute to securing future food supply. In this review,
we highlight key breakthroughs in plant genome sequencing and explain how the presence of
these genome resources in combination with gene editing techniques has revolutionized the
procedures of trait discovery and manipulation. Adoption of new approaches such as speed
breeding, genomic selection and haplotype-based breeding could overcome several limitations of
conventional breeding. We advocate that strengthening varietal release and seed distribution
systems will play a more determining role in delivering genetic gains at farmerâs field. A holistic
approach outlined here would be crucial to deliver steady stream of climate-smart crop cultivars
for sustainable agriculture
Technological perspectives for plant breeding
New Breeding Technologies? For some, both inside and outside
the scientific community, this phrase is synonymous
with gene editingâor used exclusively to describe the
application of CRISPR/Cas9 to plant improvement. Much
as, historically, the term âbiotech cropsâ has been hijacked to
only mean crop plants produced using genetic engineering.
However, âbreeding technologiesâ refers not only to
genetic modification using techniques of molecular biology,
but also to a vast number of other techniques developed
for breeding via the application of scientific advancements
emanating from disciplines such as computer science, plant
biology, statistics, automation, robotics and artificial intelligence.
This concept is not new: in reality, technology has
been a feature of crop improvement since early in the last
century..
- âŚ