Movements and Habitat Use by Temperate-Nesting Canada Geese During the Postbreeding Period in Southern Québec

Individual behavior that reduces vulnerability to predation can affect population dynamics of animals. Temperate-nesting Canada Geese (Branta canadensis maxima) have increased steadily throughout the Atlantic flyway and have become a nuisance in some parts of their range. The objective of our study was to describe movements and habitat use during the postbreeding period of Canada Geese recently established in southern Québec. More specifically, we wanted to determine whether geese were using areas where hunting was allowed to assess the potential of harvest to control the number of geese. We tracked a sample of geese fitted with radio or conventional alphanumeric collars throughout the fall in three zones characterized by different habitats and hunting pressure. Before the hunting season, geese left the breeding area where hunting was allowed to reach suburban areas where firearm discharge was prohibited or hunters’ numbers were low. These postbreeding movements occurred when juveniles were approximately three months old. We observed few local movements among zones once migrant geese from northern breeding populations reached the study area. Radio-collared geese used mainly natural habitats (75.4 ± 2.6%), followed by urban (14.4 ± 2.7%), and agricultural habitats (10.3 ± 0.8%). They were located 73.8 ± 6.2% of the time in areas where hunting was prohibited. Geese that attended their juveniles during brood rearing were more prone to use areas where firearm discharge was restricted than geese that had abandoned or lost their brood. This study shows that under the prevailing regulations, the potential of hunting to manage the increasing breeding population of Canada Geese in southern Québec is limited.

An observing system simulation experiment for climate monitoring with GNSS radio occulation data: setup and testbed study

The long-term stability, high accuracy, all-weather capability, high vertical resolution, and global coverage of Global Navigation Satellite System (GNSS) radio occultation (RO) suggests it as a promising tool for global monitoring of atmospheric temperature change. With the aim to investigate and quantify how well a GNSS RO observing system is able to detect climate trends, we are currently performing an (climate) observing system simulation experiment over the 25-year period 2001 to 2025, which involves quasi-realistic modeling of the neutral atmosphere and the ionosphere. We carried out two climate simulations with the general circulation model MAECHAM5 (Middle Atmosphere European Centre/Hamburg Model Version 5) of the MPI-M Hamburg, covering the period 2001–2025: One control run with natural variability only and one run also including anthropogenic forcings due to greenhouse gases, sulfate aerosols, and tropospheric ozone. On the basis of this, we perform quasi-realistic simulations of RO observables for a small GNSS receiver constellation (six satellites), state-of-the-art data processing for atmospheric profiles retrieval, and a statistical analysis of temperature trends in both the “observed” climatology and the “true” climatology. Here we describe the setup of the experiment and results from a test bed study conducted to obtain a basic set of realistic estimates of observational errors (instrument- and retrieval processing-related errors) and sampling errors (due to spatial-temporal undersampling). The test bed results, obtained for a typical summer season and compared to the climatic 2001–2025 trends from the MAECHAM5 simulation including anthropogenic forcing, were found encouraging for performing the full 25-year experiment. They indicated that observational and sampling errors (both contributing about 0.2 K) are consistent with recent estimates of these errors from real RO data and that they should be sufficiently small for monitoring expected temperature trends in the global atmosphere over the next 10 to 20 years in most regions of the upper troposphere and lower stratosphere (UTLS). Inspection of the MAECHAM5 trends in different RO-accessible atmospheric parameters (microwave refractivity and pressure/geopotential height in addition to temperature) indicates complementary climate change sensitivity in different regions of the UTLS so that optimized climate monitoring shall combine information from all climatic key variables retrievable from GNSS RO data.

RF Energy Harvesting in WSNs

As a vital factor affecting system cost and lifetime, energy consumption in wireless sensor networks (WSNs) has been paid much attention to. This article reviews existing energy harvesting technology applied in WSNs, and analyzes advantages of harvesting radio frequency (RF) energy in WSNs.

Social politics in a transoceanic world in the early Cold War years

This article argues that those termed 'liberals' in the United States had the opportunity in the late 1940's to use overseas case studies to reshape the ramshackle political agenda of the New Deal along more specifically social democratic lines, but hat they found it impossible to match interest in the wider world with a concrete programme to overcome tension between left-wing politics and the emerging anti-totalitarianism of the Cold War. The American right, by contrast, conducted a highly organised publicity drive to provide new meaning for their anti-statist ideology in a post-New Deal, post-isolationist United States by using perceived failures of welfare states overseas as domestic propaganda. The examples of Labour Britain after 1945 and Labour New Zealand both provided important case studies for American liberals and conservatives, but in the Cold War it was the American right who would benefit most from an ideologically driven repackaging of overseas social policy for an American audience.

Forces information and media services in Operation Granby 1990-91

The paper looks at the setting up of media services for British Army forces engaged in Operation Granby, the British participation in Operation Desert Storm, the liberation of Kuwait from Iraqi occupation in 1991. In particular, the piece focuses on the creation of a force newspaper and radio station.There is far more involved in the organisation of modern war than simply battles themselves One aspect is the importance of creating and maintaining morale, which can be achieved in a number of ways, especially by keeping troops informed of their progress, purpose and mission as operations unfold. This was specifically recognised by commanders in the Gulf War, who ensured the smooth transmission of information by the provision of media services for forces personnel throughout the War. Here S J Anglim concentrates on the difficulties inherent in setting up and running the Gulf Forces newspaper, The Sandy Times, a Radio service and producing video reviews, all of which played their part in ensunng high morale. He concludes that there are lessons to be learnt and implemented for the success of any future conflicts.

Forward modelling to determine the observational signatures of white-light imaging and interplanetary scintillation for the propagation of an interplanetary shock in the ecliptic plane

Recent coordinated observations of interplanetary scintillation (IPS) from the EISCAT, MERLIN, and STELab, and stereoscopic white-light imaging from the two heliospheric imagers (HIs) onboard the twin STEREO spacecraft are significant to continuously track the propagation and evolution of solar eruptions throughout interplanetary space. In order to obtain a better understanding of the observational signatures in these two remote-sensing techniques, the magnetohydrodynamics of the macro-scale interplanetary disturbance and the radio-wave scattering of the micro-scale electron-density fluctuation are coupled and investigated using a newly constructed multi-scale numerical model. This model is then applied to a case of an interplanetary shock propagation within the ecliptic plane. The shock could be nearly invisible to an HI, once entering the Thomson-scattering sphere of the HI. The asymmetry in the optical images between the western and eastern HIs suggests the shock propagation off the Sun–Earth line. Meanwhile, an IPS signal, strongly dependent on the local electron density, is insensitive to the density cavity far downstream of the shock front. When this cavity (or the shock nose) is cut through by an IPS ray-path, a single speed component at the flank (or the nose) of the shock can be recorded; when an IPS ray-path penetrates the sheath between the shock nose and this cavity, two speed components at the sheath and flank can be detected. Moreover, once a shock front touches an IPS ray-path, the derived position and speed at the irregularity source of this IPS signal, together with an assumption of a radial and constant propagation of the shock, can be used to estimate the later appearance of the shock front in the elongation of the HI field of view. The results of synthetic measurements from forward modelling are helpful in inferring the in-situ properties of coronal mass ejection from real observational data via an inverse approach.

Investigating the practicality of using radio tracking to determine home range and movements of Picathartidae

Radiotelemetry is an important tool used to aid the understanding and conservation of cryptic and rare birds. The two bird species of the family Picathartidae are little-known, secretive, forest-dwelling birds endemic to western and central Africa. In 2005, we conducted a radio-tracking trial of Grey-necked Picathartes Picathartes oreas in the Mbam Minkom Mountain Forest, southern Cameroon, using neck collar (two birds) and tail-mounted (four birds) transmitters to investigate the practicality of radio-tracking Picathartidae. Three birds with tail-mounted transmitters were successfully tracked with the fourth, though not relocated for radio tracking, resighted the following breeding season. Two of these were breeding birds that continued to provision young during radio tracking. One neck-collared bird was found dead three days after transmitter attachment and the other neither relocated nor resighted. As mortality in one bird was potentially caused by the neck collar transmitter we recommend tail-mounted transmitters in future radio-tracking studies of Picathartidae. Home ranges, shown using minimum convex polygon and kernel estimation methods, were generally small (<0.5 km(2)) and centred around breeding sites. A minimum of 60 fixes were found to be sufficient for home range estimation.

Prevalence of subclinical mastitis and associated risk factors in smallholder dairy cows in Tanzania

A cross-sectional study was carried out on 200 randomly selected farms in each of the Iringa and Tanga regions of Tanzania to estimate the prevalence and risk factors for subclinical mastitis in dairy cows kept by smallholders. Subclinical mastitis was assessed using the California mastitis test (CMT), and by the bacteriological culture of 1500 milk samples collected from 434 clinically normal cows. The percentages of the cows (and quarters) with subclinical mastitis were 75.9 per cent (46.2 per cent) when assessed by the CMT and 43.8 per cent (24.3 per cent) when assessed by culture. Factors significantly associated with an increased risk of a CMT-positive quarter were Boran breed (odds radio [OR]=3.51), a brought-in cow (rather than homebred) (OR=2.39), peak milk yield, and age. The stripping method of hand milking was associated with a significantly lower prevalence Of CMT-positive quarters (OR=0.51). The CMT-positive cows were more likely to be culture positive (OR=4.51), as were brought-in (OR=2.10) and older cows.

The long-term effect of active immunization against inhibin in goats

This experiment addresses the long-term effect of active immunization of goats against a recombinant ovine inhibin alpha subunit (roIHN-alpha). In late anestrus 100 mu g of roINH-alpha was administered to 40 pluriparous Boer goat does, followed, 4 weeks later, by a booster injection. Weekly blood samples were drawn to monitor the inhibin binding capacity with the aid of a radio-tracer binding assay. From the onset until 48 h after the end of each estrus, follicular development and ovulation rate were monitored at 24 h intervals by transrectal ultrasonography. Beginning in August and continuing into January, does were mated at every other estrus, and submitted to transcervical embryo collection. Seven months after the first immunization, the does were mated again and permitted to carry to term. All immunized does produced inhibin antibodies, an elevated titre being first detected 2 weeks after primary immunization. Maximum titres were reached after 6 weeks, i.e. 2 weeks after the booster injection. Thereafter, in the course of the following 32 weeks, the titre subsided gradually. The does started cycling by mid-August. At that stage the average number of follicles more than 4 mm in diameter, ovulations and total embryos and ova recovered were 14.7 (+/- 2.3), 5.3 (+/- 0.7) and 4.4 (+/- 1.0), respectively. A steady decline followed and in January the corresponding means were: 5.2 (+/- 0.6) follicles, 3.1 (+/- 0.6) ovulations and 1.2 (+/- 0.4) embryos and ova recovered. When mated toward the end of the breeding season, 85% of the does became pregnant to the first mating and 73% went to term. Healthy kids were born, the average litter size being 2.2 (+/- 0.1). In conclusion, immunization of goats against a recombinant inhibin alpha-subunit proved to be a practicable means of producing embryos for transfer purposes. After about half a year, when the inhibin antibody titre has subsided, it is possible to return the does to the breeding flock without risking complications with normal breeding activity. (c) 2009 Elsevier Inc. All rights reserved.

Superovulation and embryo collection in nulliparous Boer goat does immunized against a recombinant ovine alpha-subunit inhibin

With the purpose of eliciting a superovulatory response, 12 adult nulliparous Boer goat does were actively immunized against a recombinant a-subunit of ovine inhibin (roIHN-alpha; two injections of 100 mg 4 weeks apart). Another 12 control Boer goat does were treated with physiological saline and acted as controls. One year later the immunized animals were boostered by the administration of another dose (100 mg) of the immunogen. Following treatment, blood samples were collected twice weekly for the periods of 16 and 12 weeks, respectively, to monitor the inhibin binding ability with the aid of a radio-tracer binding assay. Throughout the experiment, estrus detection was conducted twice daily with the aid of an aproned intact buck. From the first day after treatment to 48 h after standing estrus, ovarian activity was monitored daily by transrectal ultrasonography. On alternate estrous cycles, does were mated and 6 days later flushed transcervically to recover embryos. All goats treated with the roIHN-alpha produced antibodies reactive to the native bovine inhibin tracer-the titre increasing from 2.9 +/- 0.4 to a maximum of 21.9 +/- 2.9% binding after the second injection. The antibody titre gradually subsided over the next 16 weeks. The booster injection restored an elevated antibody titre (11.7 +/- 0.4%), which was maintained until the end of the sampling period 12 weeks later. In the control goats only trace amounts of antibody were recorded throughout the trial. In the roIHN-alpha-immunized goats the number of follicles reaching a diameter of > 4 mm was 14.6 +/- 1.2 per doe. A positive correlation was recorded between the follicle number and antibody titre (r=0.61; P < 0.01). The number of follicles ovulating per doe (6.9 +/- 0.7) followed the same tendency-however, the proportion decreased with increasing follicle numbers. A relatively weak correlation was recorded between the inhibin binding ability and number of ovulations (r=0.27; P < 0.05). In the control goats the majority (92%) of follicles exceeding 4 mm in diameter ovulated (2.5 +/- 0.1 follicles/doe). Embryo collection proved unsatisfactory (42% versus 39% recovery for immunized and control animals, respectively)-presumably because the uterine lumen of the nulliparous does was too narrow to permit effective flushing. In the group of immunized goats the occurrence of short estrous cycles (< 15 days) recorded was 34% versus only 6% in the controls. Overall, immunization of goats against roIHN-alpha led to an almost six-fold increase in number of ovarian follicles, a three-fold increase in ovulations and, despite the low recovery rate, a more than three-fold increase in ova or embryos recovered. It may be concluded that treatment of female goats with roIHN-alpha leads to an inhibin antibody response, accompanied by enhanced ovarian activity. The response was, however, accompanied by a large proportion of retained follicles and a high incidence of short estrous cycles. These problems need to be further investigated before rendering the method fit for application in embryo transfer programs in goats. (C) 2007 Elsevier B.V. All rights reserved.

Movements, activity patterns and home range of a female brown bear (Ursus arctos, L.) in the Rodopi Mountain Range, Greece

Movements and activity patterns of an adult radio-tagged female brown bear accompanied by her cubs were documented for the first time in Rodopi area (NE Greece) from August 2000 to July 2002. Average daily movements were 2.45 +/- 2.26 SD km, (range 0.15-8.5 km). The longest daily range could be related to human disturbance (hunting activity). The longest seasonal distance (211 km), during Summer 2001 coincided with the dissolution of the family. With cubs, the female was more active during daytime (73 % of all radio-readings) than when solitary (28 %). The female switched to a more crepuscular behaviour, after separation from the yearling (July 2001). According to pooled data from 924 activity - recording sessions, during the whole monitoring period, the female was almost twice as active during day time while rearing cubs (51 % active) than when solitary (23 %). The autumn and early winter home range size of the family was larger (280 km(2)) than after the separation from the cubs (59 km(2)). During the family group phase, home range size varied from 258 km(2) in autumn to 40 km(2) in winter (average denning period lasted 107 days : December 2000-March 2001). The bear hibernated in the Bulgarian part of the Rodopi Range during winters of 2001 and 2002.

Putting the coke in coke

The story of cocaine: from royalty to popular refresher... Surprising as it sounds, Coca Cola gets its name from one of its original ingredients - cocaine. And although the drug's now illegal, this wasn't always the case. But how did it become popular, what led to its downfall, and how does Coca Cola come in to it?

Energy saving in intelligent buildings - via energy harvesting in wireless sensor networks

Wireless sensor networks (WSNs) have been widely used in pervasive systems such as intelligent buildings. As a vital factor of product cost, energy consuming in WSN has been focused upon, but only via energy harvesting can the problem be overcome radically. This article presents a new approach to harvesting electromagnetic energy for WSN from useless radio frequency (RF) signals transmitted in WSN, with a quantitative analysis showing its feasibility.

Performance of asynchronous channel assignment scheme in non-uniform and dynamic topology WLANs

Dense deployments of wireless local area networks (WLANs) are fast becoming a permanent feature of all developed cities around the world. While this increases capacity and coverage, the problem of increased interference, which is exacerbated by the limited number of channels available, can severely degrade the performance of WLANs if an effective channel assignment scheme is not employed. In an earlier work, an asynchronous, distributed and dynamic channel assignment scheme has been proposed that (1) is simple to implement, (2) does not require any knowledge of the throughput function, and (3) allows asynchronous channel switching by each access point (AP). In this paper, we present extensive performance evaluation of this scheme when it is deployed in the more practical non-uniform and dynamic topology scenarios. Specifically, we investigate its effectiveness (1) when APs are deployed in a nonuniform fashion resulting in some APs suffering from higher levels of interference than others and (2) when APs are effectively switched `on/off' due to the availability/lack of traffic at different times, which creates a dynamically changing network topology. Simulation results based on actual WLAN topologies show that robust performance gains over other channel assignment schemes can still be achieved even in these realistic scenarios.

Impact of interference on throughput in dense WLANs with multiple APs

The popularity of wireless local area networks (WLANs) has resulted in their dense deployments around the world. While this increases capacity and coverage, the problem of increased interference can severely degrade the performance of WLANs. However, the impact of interference on throughput in dense WLANs with multiple access points (APs) has had very limited prior research. This is believed to be due to 1) the inaccurate assumption that throughput is always a monotonically decreasing function of interference and 2) the prohibitively high complexity of an accurate analytical model. In this work, firstly we provide a useful classification of commonly found interference scenarios. Secondly, we investigate the impact of interference on throughput for each class based on an approach that determines the possibility of parallel transmissions. Extensive packet-level simulations using OPNET have been performed to support the observations made. Interestingly, results have shown that in some topologies, increased interference can lead to higher throughput and vice versa.