Gaining from Improved Dairy Cow Nutrition: Economic, environmental and animal health benefits

A majority of UK dairy herds have the potential to increase profitability by improving the ration of their cows. This paper reports that gains averaging around £100 per cow have been made within one year of adopting the Keenan Hi-Fibre ration by 239 UK herds in 2006 and 2007. Larger gains have been made by herds in France. The key performance indicator underlying these gains is Feed Conversion Efficiency, whereby the same, or even a smaller amount of Dry Matter Intake generates higher yields per cow. Importantly, the gains are associated with large improvements in animal health and reductions in greenhouse gases per litre of milk produced.Feed conversion efficiency, cattle nutrition, greenhouse gas emissions, animal health., Livestock Production/Industries,

Isolation and identification of fungal species from dried date palm (Phoenix dactylifera) fruits sold in Maiduguri metropolis

A total of 360 dried date palm (Phoenix dactylifera) fruits were collected from hawkers, shops and market places within Maiduguri metropolis for the detection of the presence of fungal species. Investigation was based on cultural, microscopically and biochemical tests. Of the 327 (90.83%) fungal isolates recovered on Sabouraud dextrose agar (SDA), Aspergillus niger had the highest percentage of occurrence (39.17%), followed by Aspergillus flavus (17.60%), Mucor species (16.67%), Aspergillus fumigatus (12.50%), Trychophyton rubrum (4.16%), while Candida albicans had the least percentage of occurrences of (0.83%). There is need therefore to appropriately treat this fruit before consumption, to minimize possible mycotic infection.Keywords: Isolation, fungi, date palm, Phoenix dactylifera, Maidugur

High-performance light-weight electrodes for hydrogen-oxygen fuel cells

High performance light weight electrodes for hydrogen oxygen fuel cell

Reindeer and caribou (Rangifer tarandus) response towards human activities

We address the question of how human activities and infrastructure influence reindeer/caribou’s (Rangifer tarandus) behaviour and habitat use and review studies based on current methodologies. Anthropogenic activities have a direct affect on Rangifer behaviour through the senses hearing, sight and smell, and all of these are important tools for behavioural risk assessment. Short term indirect responses, such as habituation, sensitisation, avoidance, and displacement, develop through neutral, positive or negative associations towards stimulus in terms of Rangifer’s ability to experience, learn, and remember. Long term behavioural responses develop through interaction with predators and, for reindeer, also domestication. A survey of the literature dealing with behavioural studies reveals that although Rangifer in most cases retreat from anthropogenic activities, comfort distances (i.e. distances beyond which animal behaviour or activity are not influenced) are relatively short. In most cases, energetic implications appear moderate and small compared to other natural, biotic influences such as disturbance (and death) caused by insect and/or predator harassment. Unless obstructing access, physical constructions of various kinds apparently have limited effects on Rangifer behaviour or habitat use. On the other hand, constructions that do obstruct or limit access and recreational or other motorized and non-motorized activities appear to have stronger impacts on avoidance and redistribution of Rangifer. Behavioural effects that might decrease survival and reproduction include retreat from favourable habitat near disturbance sources and reduction of time spent feeding with resulting energy depletion over time. Rangifer habitat use, habitat avoidance, and feeding preferences are governed by a complexity of natural interacting factors. Domestication, habituation and sensitisation are essential in shaping Rangifer’s adaptability, and should be included in future studies on reindeer and caribou responses towards various anthropogenic activities. Although cumulative effects from human activities are likely, it remains difficult to separate these from natural variations in Rangifer habitat use and demography. Habitat avoidance towards various human infrastructures and activities is reported, but most studies reporting relatively far (4-25 km) avoidance distances relied on measurements of range properties and animal distribution recorded on 1-2 days annually in winter to induce a potential response from the animals and lack important environmental variables and/or alternative hypothesises. This methodology should be improved in order to enable identification of correlation versus causation. Studies relying on animal behaviour measurements can more correctly identify and test responses to various stimuli while also controlling for degree of domestication and other various environmental variables, but only in a limited time and spatial scale. Furthermore, such studies may not necessarily capture potential population consequences from disturbances. Thus, there are important weaknesses in the two leading methodologies (measuring animal behaviour and indirectly mapping regional/population movements and habitat use through measurements of range properties). To best study Rangifer’s responses towards anthropogenic infrastructure and activities, we propose that the two methodologies be combined and supplied with modern GPS/telemetry.Abstract in Norwegian / Sammendrag:Rein og caribous reaksjon på forskjellige menneskelige aktiviteter og installasjoner Vi adresserer spørsmålet om hvordan menneskelig aktivitet og infrastruktur påvirker rein/caribous (Rangifer tarandus) atferd og områdebruk og gjennomgår publiserte arbeider basert på aktuelle metoder. Antropogene aktiviteter har direkte effekt på reinens atferd via hørsel, syn og lukt; alle er viktige for deres risikovurdering. Kortsiktige indirekte reaksjonsmønstre, slik som habituering, sensitivisering, unnvikelse og fortrengning utvikles gjennom nøytrale, positive eller negative opplevelser av stimuli i henhold til erfaring, læring og hukommelse. Utviklingen av permanente atferdsmønstre skjer ved samvirke med predatorer og for reinens del, også ved domestisering. En litteraturoversikt om atferdsstudier viser at selv om Rangifer i de fleste tilfeller unnviker antropogene virksomheter, så er de avstander dyrene velger å ha mellom seg og infrastruktur uten at normalatferden endres, relativt korte. De energimessige implikasjonene er også beskjedne sammenlignet med virkningen av naturlige stressfaktorer så som forstyrrelser (og død) forårsaket av insekter og predatorer. Fysiske installasjoner av ulik art har også begrenset effekt med mindre de fysisk hindrer Rangifers områdebruk. På den annen side vil fysiske installasjoner, som hindrer eller begrenser bruken av områder, og trafikk, både fottrafikk og trafikk med motorkjøretøy, kunne ha sterkere virkning på unnvikelsesatferd og områdebruk. Atferdsmessige effekter som kan redusere overlevelse og reproduksjon omfatter unnvikelse fra beiteområder nær forstyrrelseskilder. For Rangifer er det negative resultatet av dette øket aktivitet, redusert beitetid og nedbygging av energireserver. Rangifers områdebruk, unnvikelsesatferd og næringspreferanser bestemmes ut fra et kompleks av naturlige og gjensidig påvirkende faktorer. Domestisering, habituering og sensitivisering som er sentrale begrep i utformningen av Rangifers tilpasningsevne, bør inkluderes i fremtidige studier av rein og caribous reaksjon på antropogene aktiviteter. Selv om en kumulativ atferdseffekt av menneskelige aktiviteter er mulig, er det vanskelig å skille slike fra naturlige variasjoner som følge av variasjoner i områdebruk og bestandsdynamiske forhold. Habitatunnvikelse som følge av menneskelig påvirkning er rapportert. De fleste studiene som rapporterer relativt lange unnvikelsesavstander (4-25 km) er imidlertid basert på målinger av beiteslitasje og lokalisering av dyr registrert i løpet av 1-2 dager årlig i løpet av vinteren og mangler viktige miljøparametere og/eller alternative hypoteser. Denne metoden bør forbedres for å kunne skille mellom korrelasjon og kausalitet. Målinger av atferd gjør mulig en mer korrekt testing av Rangifers reaksjon på ulike antropogene stimuli samtidig som man kontrollerer for graden av domestisering og forskjellige miljøfaktorer. Atferdsstudiene avgrenses imidlertid i både tid og rom og vil vanligvis ikke fange opp eventuelle bestandsdynamiske konsekvenser av forstyrrelser. Det hefter følgelig svakheter ved begge de to dominerende metodene som i dag anvendes; måling av atferd og bestandsfordeling og indirekte kartlegging av områdebruk ved måling av beiteslitasje. For å oppnå en bedre studiedesign for måling av Rangifers reaksjon på antropogen infrastruktur og tilknyttede aktiviteter foreslår vi at de to metodene kombineres og suppleres med GPS/telemetri teknologi

Concentrations and snow-atmosphere fluxes of reactive nitrogen at Summit, Greenland

Concentrations and fluxes of NOy (total reactive nitrogen), ozone concentrations and fluxes of sensible heat, water vapor, and momentum were measured from May 1 to July 20, 1995 at Summit, Greenland. Median NOy concentrations declined from 947 ppt in May to 444 ppt by July. NOy fluxes were observed into and out of the snow, but the magnitudes were usually below 1 μmol m−2 h−1 because of the low HNO3 concentration and weak turbulence over the snow surface. Some of the highest observed fluxes may be due to temporary storage by equilibrium sorption of peroxyacetylnitrate (PAN) or other organic nitrogen species on ice surfaces in the upper snowpack. Sublimation of snow at the surface or during blowing snow events is associated with efflux of NOy from the snowpack. Because the NOy fluxes during summer at Summit are bidirectional and small in magnitude, the net result of turbulent NOyexchange is insignificant compared to the 2 μmol m−2 d−1 mean input from fresh snow during the summer months. If the arctic NOy reservoir is predominantly PAN (or compounds with similar properties), thermal dissociation of this NOy is sufficient to support the observed flux of nitrate in fresh snow. Very low HNO3 concentrations in the surface layer (1% of total NOy) reflect the poor ventilation of the surface layer over the snowpack combined with the relatively rapid uptake of HNO3 by fog, falling snow, and direct deposition to the snowpack

IrSr_2Sm_{1.15}Ce_{0.85}Cu_{2.175}O_{10}: A Novel Reentrant Spin-Glass Material

A new iridium containing layered cuprate material, IrSr_2Sm_{1.15}Ce_{0.85}Cu_{2.175}O_{10, has been synthesized by conventional ambient-pressure solid-state techniques. The material's structure has been fully characterized by Rietveld refinement of high resolution synchrotron X-ray diffraction data; tilts and rotations of the IrO_6 octahedra are observed as a result of a bond mismatch between in-plane Ir-O and Cu-O bond lengths. DC-susceptibility measurements evidence a complex set of magnetic transitions upon cooling that are characteristic of a reentrant spin-glass ground-state. The glassy character of the lowest temperature, Tg=10 K, transition is further confirmed by AC-susceptibility measurements, showing a characteristic frequency dependence that can be well fitted by the Vogel-Fulcher law and yields a value of \Delta_(T_f)/[T_f \Delta log({\omega})] =0.015(1), typical of dilute magnetic systems. Electronic transport measurements show the material to be semiconducting at all temperatures with no transition to a superconducting state. Negative magnetoresistance is observed when the material is cooled below 25 K, and the magnitude of this magnetoresistance is seen to increase upon cooling to a value of MR = -9 % at 8 K

Contextualizing Leadership Upon Followers’ Unique Characteristics: An Argument for Explicit Consideration of Accurate Person Perception

Leadership scholarship, in terms of theories and models, continues to make risky assumptions that the person in a leader role accurately accounts for not only follower behavior, but also the motives and personality aspects from which said behaviors manifest. In this paper we propose an integrated path model that utilizes both Leader-Member Exchange and Transformational Leadership, while explicitly focusing on the science behind interpersonal judgment accuracy. It is only by having an accurate understanding of the follower, which has been a long held untested assumption, can congruence be purposely obtained, narrowing the gap between ideology and practice

The resistance of randomly grown trees

Copyright @ 2011 IOP Publishing Ltd. This is a preprint version of the published article which can be accessed from the link below.An electrical network with the structure of a random tree is considered: starting from a root vertex, in one iteration each leaf (a vertex with zero or one adjacent edges) of the tree is extended by either a single edge with probability p or two edges with probability 1 − p. With each edge having a resistance equal to 1 omega, the total resistance Rn between the root vertex and a busbar connecting all the vertices at the nth level is considered. A dynamical system is presented which approximates Rn, it is shown that the mean value (Rn) for this system approaches (1 + p)/(1 − p) as n → ∞, the distribution of Rn at large n is also examined. Additionally, a random sequence construction akin to a random Fibonacci sequence is used to approximate Rn; this sequence is shown to be related to the Legendre polynomials and its mean is shown to converge with |(Rn) − (1 + p)/(1 − p)| ∼ n−1/2.Engineering and Physical Sciences Research Council (EPSRC