Perimeter Fence Research Articles

Wildlife friendly fence designs and elk fence crossing behavior

AbstractFencing is a ubiquitous feature of our agricultural landscape. Fences necessarily have the potential to reduce habitat connectivity for resident ungulate populations. Unsuccessful fence crossings have the potential to cause injury or death to wildlife, as well as resulting in damage to the fence in terms of time and maintenance costs. Wildlife friendly fence designs may provide landowners and ungulate managers the opportunity to mitigate risks associated with wildlife crossings. Using remote cameras (n = 12) along the perimeter fence of the Wainwright Dunes Ecological Reserve, Alberta, we quantified and compared elk crossing behaviors at standard 4 strand fences and gates as well as 3 strand fences and gates both with experimentally modified top and bottom strand heights. We found that wildlife friendly designs promoted behavioral options for elk of various demographic classes to cross fences. Our results suggest that the number of strands and the height of the top and bottom strand are important determinants for animals deciding to cross over, through, or under fences. While difficult or problematic crossings were primarily determined by how the individual crossed and made up a proportionally small number of crossings, the sheer volume of crossings we observed suggests that any modification which increases fence permeability to elk will likely result in less damage to fences and the crossing individuals.

Analysis of Weed Communities in Solar Farms Located in Tropical Areas—The Case of Malaysia

Weed management in large-scale solar photovoltaic (LSS-PV) farms has become a great concern to the solar industry due to scarcity of labour and the ever-increasing price of pesticides, which opens up possibilities for integrated farming, also known as agrivoltaics. Improper weed control may have multiple negative impacts such as permanent shading of the module surface, pest housing which damages communication cables, and even bush fires. The shaded PV modules can be heated up to extreme temperatures, causing costly burn-out damage. Critical information on the types of weeds on solar farms, especially in Malaysia, has not been established to support the concept of weed management. Thus, with this study, detailed composition of the weed community was obtained via quadrat sampling between solar PV modules, near ground equipment, near perimeter fencing, and directly underneath the PV modules. Weed-control measures via high-quality weedmat installation under solar PV arrays have been implemented where this approach can be considered effective on solar farms based on the existing PV structure height and equipment constraints plus the increasing cost for labour and agricultural inputs. This work underlines the proposed Agrivoltaic for Large Scale Solar (Agrivoltaic4LSS) program to complement the solar industry in Malaysia towards an agrivoltaic, eco-friendly approach to weed management.

The First 3 Years: Movements of Reintroduced Plains Bison (Bison bison bison) in Banff National Park

We assessed 3 years of post-release movements of a reintroduced plains bison (Bison bison bison) population for evidence of anchoring, settling, exploratory and adaptive behavior within a 1200 km2 target reintroduction zone in Banff National Park. We first held them in a soft-release pasture for 18 months, then partially constrained their movements with drift fences and hazing trials to discourage excursions from a 1200 km2 target reintroduction zone. Their post-release movements were within 13 km of the soft-release pasture for the first 3 months, but management interventions were needed to keep the animals within 29 km of the release site and inside the reintroduction zone for the remainder of the 3-year study period. Bison exploration was high in the first year but decreased thereafter, as did the size of their annual home range. Step lengths did not decrease but the frequency of “surge movements” (step lengths > 4 km in 2 h) did. Fence visits did not decrease over time but the need to herd/haze the bison from other, unfenced boundary areas did. The reintroduced bison seasonally selected for rugged, high-elevation habitat despite being translocated from a flat landscape. Our results suggest wild bison reintroductions to areas of just a few hundred square kilometres are possible without perimeter fencing, so long as good habitat and management interventions to discourage broad movements are in place. Trends suggest such interventions will need to continue in Banff until the bison range can be expanded and/or bison movements are constrained by other forces, such as regulated hunting outside the park.

Using Virtual Fencing to Create Fuel Breaks in the Sagebrush Steppe

Wildfires are increasingly impacting ecosystem processes and ecological services provided by sagebrush rangelands in the western United States. Mitigating this problem involves actions taken before, during, and after fire. In recent years, there has been increased emphasis on prefire fuel management, including fuel breaks. Cattle grazing can be used as a tool to manage fine fuel loading within fuel breaks; however, spatially focusing grazing impacts inside a linear fuel break is challenging. We evaluated using virtual fencing (VF) technology for concentrating grazing impacts inside a 200-m wide, 3-km long fuel break within a 410-ha pasture in sagebrush steppe. The fuel break was bounded by four 35-m wide virtual fences, each consisting of boundaries for auditory (10-m wide) and electrical cues (25-m wide), and a traditional 5-strand barbed wire perimeter fence delineated the pasture perimeter. In June 2021 we introduced 16 dry cows and 23 cow/calf pairs into the fuel break following a 5-d VF training period; cattle were removed after 30 d. Cows were fitted with VF collars (calves not collared) that use Global Positioning System positioning to contain cattle inside fuel break boundaries and record animal locations at 5-min intervals. End-of-trial forage utilization was 48.5% ± 3.7% and 5.5% ± 0.7% for areas inside and outside of the fuel break, respectively. Daily percentage of cattle locations inside the fuel break was initially > 94% but declined to approximately 75% by the end of the trial. Percentage daily locations of dry cows and cow/calf pairs inside the fuel break was 98.5% ± 0.5% and 80.6% ± 1.1%, respectively (P < 0.001). Our data suggest virtual fencing can be a highly effective method of concentrating grazing to reduce herbaceous fuel biomass within linear fuel breaks. Efficacy of this method could be substantially impacted by use of dry versus cow/calf pairs.

The efficacy of wildlife fences for keeping reindeer outside a chronic wasting disease risk area

Abstract Emerging wildlife diseases often comes with negative cultural and economic impact. Limiting disease spread is a recurrent goal and challenge, but the efficacy of various mitigation measures is rarely assessed. Chronic wasting disease (CWD) is a lethal disease among cervids that was discovered among alpine reindeer (Rangifer tarandus) in the Nordfjella mountain range of Norway in 2016. After de‐population, the entire range was fallowed to avoid re‐emergence from environmental pathogen reservoirs. This involved installing perimeter fences in the alpine areas in order to keep reindeer from adjacent populations outside of the CWD risk area, while other cervids (red deer Cervus elaphus, roe deer Capreolus capreolus and moose Alces alces) were likely to enter through the forested areas. We used camera trapping and surveillance reports to assess the efficacy of the perimeter fences. All four species of cervids were documented inside the CWD risk area. For reindeer, only 12.0% of observations were inside the CWD risk area, while this was 28.7% for the other cervids. The higher proportion of observations outside of the fenced area indicate that fences provided a barrier and lowered the number of crossings also of red deer, roe deer and moose. Fences do not provide complete barriers, and we discuss practical solutions for how to avoid ‘intruders’ entering a given area, such as maintenance at critical points (e.g. river and road crossings) and height of fences (e.g. species variation in jumping; deep snow) to uphold their desired effect. We argue that two fence lines with a buffer zone would be required when re‐introduction of reindeer are planned in the CWD risk area after fallowing, similar to what has been suggested for other wildlife diseases.

Image Edge Detection Methods in Perimeter Security Systems Using Distributed Fiber Optical Sensing.

This paper aims to evaluate detection algorithms for perimeter security systems based on phase-sensitive optical time-domain reflectometry (-OTDR). Our own designed and developed sensor system was used for the measurement. The main application of the system is in the area the perimeter fencing intrusion detection. The system is unique thanks to the developed motherboard, which contains a field-programmable gate array (FPGA) that takes care of signal processing. This allows the entire system to be integrated into a 1U rack chassis. A polygon containing two different fence types and also cable laid underground in a plastic tube was used for testing. Edge detection algorithms using the Sobel and Prewitt operators are considered for post-processing. The comparison is made based on the signal-to-noise ratio (SNR) values calculated for each event. Results of algorithms based on edge detection methods are compared with the conventional differential method commonly used in -OTDR systems.

Humoral immunity at the brain borders in homeostasis.

The meninges encase the brain and spinal cord and house a variety of immune cells, including developing and mature B cells, and antibody-secreting plasma cells. In homeostasis, these cells localize around the dural venous sinuses, providing a defense 'zone' to protect the brain and spinal cord from blood-borne pathogens. Dural plasma cells predominantly secrete IgA antibodies, and some originate from the gastrointestinal tract, with the number and antibody isotype shaped by the gut microbiome. For developing B cells arriving from the adjacent bone marrow, the dura provides a site to tolerize against central nervous system antigens. In this review, we will discuss our current understanding of meningeal humoral immunity in homeostasis.

A feasibility study on the application of mesh grids for heliostat wind load reduction

This study examines the effectiveness of mesh grids in heliostat field perimeter fences and edge-mounted devices for heliostat wind load reduction. Two experimental studies were conducted: (1) the effect of mesh porosity and non-dimensional longitudinal distance of a perimeter fence upstream on the forces on a heliostat, and (2) the effect of mesh porosity and non-dimensional height-chord ratio of a heliostat edge-mounted mesh device on the heliostat loads. The experiments were conducted using an instrumented heliostat model positioned in the atmospheric test section of the Adelaide Wind Tunnel. It was found that perimeter mesh fences reduce peak loads by up to 50% and edge-mounted porous mesh devices reduce peak loads by up to 30% at the expense of increasing loads at different elevation angles. The porosity and height-chord ratio of an edge-mounted mesh were found to be important parameters influencing the maximum drag and lift reductions in operating and stow positions. The results of this work show the potential of mesh grids for reducing wind load on heliostats, and the importance of conducting a detailed techno-economic analysis on mesh grids throughout a heliostat field. The application of mesh grids on commercial-scale heliostats requires a further evaluation of the reduction of heliostat wind loads and thus cost of a field through mitigation of the incoming ABL turbulence and wake-induced turbulence from upstream heliostats.

Utility‐scale solar impacts to volant wildlife

AbstractTo reduce carbon emissions from fossil fuel combustion, United States government agencies, including those in California, initiated aggressive programs to hasten development of utility‐scale solar energy. Much of California's early development of solar energy occurred in deserts and annual grasslands, much of it on public land. Measurement of solar energy's impacts to wildlife has been limited to mortality caused by features of solar facilities, and has yet to include impacts from habitat loss and energy transmission. To estimate species‐specific bird and bat fatality rates and statewide mortality, I reviewed reports of fatality monitoring from 1982 to 2018 at 14 projects, which varied in duration, level of sampling, search interval, search method, and carcass detection trials. Because most monitors performed carcass detection trials using species of birds whose members were larger than birds and bats found as fatalities, I bridged the monitors' onsite trial results to offsite trial results based on the same methods but which also measured detection probabilities across the full range of body sizes of species represented by fatalities. This bridge preserved the project site's effects on detection probabilities while more fully adjusting for the effects of body size. My fatality estimates consistently exceeded those reported. Projected to California's installed capacity of 1,948.8 MW of solar thermal and 12,220 MW of photovoltaic (PV) panels in 2020 (14,168.8 MW total), reported estimates would support an annual statewide fatality estimate of 37,546 birds and 207 bats, whereas I estimated fatalities of 267,732 birds and 11,418 bats. Fatalities/MW/year averaged 11.61 birds and 0.06 bats at PV projects and 64.61 birds and 5.49 bats at solar thermal projects. Fatalities/km/year averaged 113.16 birds and zero bats at generation tie‐ins, and 14.44 birds and 2.56 bats along perimeter fences. Bird fatality rates averaged 3 times higher at PV projects searched by foot rather than car. They were usually biased low by insufficient monitoring duration and by the 22% of fatalities that monitors could not identify to species. I estimated that construction grading for solar projects removed habitat that otherwise would have supported nearly 300,000 birds/year. I recommend that utility‐scale solar energy development be slowed to improve project decision‐making, impacts assessment, fatality monitoring, mitigation efficacy, and oversight.

VARIATION OF NATURAL VENTILATION WITH FLOOR LEVEL AND ORIENTATION OF CLASSROOMS

In recent times, the multi-story school building has emerged as a new trend in Nigeria due to land cost in the urban area and population increase due to urban migration resulting from insecurity in rural areas. Among other factors, the floor level and space orientation are believed to affect its natural ventilation. Electricity per capita consumption in Nigeria is very low, suggesting passive ventilation in the building. The ventilation in the classroom is usually through wind-driven systems (windows). The study sought to establish the variation of natural ventilation among classrooms on different floor levels and orientations. In the ex-post facto design, instruments were employed to observe wind speeds and directions in and around selected classrooms in a school building block with two wings on three-floor levels, a perimeter fence, and a built-up residential area. The classrooms on the ground floor were half-opened casement windows, while those on the upper floors had sliding windows. Data generated were subjected to descriptive statistical analysis. In the longer wing classrooms, the mean wind speed and standard deviation obtained were 0.17m/s and 0.123 on the ground floor; 0.15m/s and 0.104 on the first floor; and 0.18m/s 0.126 on the second floor. Corresponding results in the shorter wing classrooms were 0.12m/s and 0,077 on the ground floor; 0.11m/s and 0.095 on the first floor; and 0.17m/s and 0.126 on the second floor. Ventilation coefficients were 0.13, 0.11, and 0.13 respectively on the ground, first, and second floors in the longer wing classrooms, while those in the shorter wing classrooms were 0.13, 0.12, and 0.19 respectively. The findings revealed some direct variation in natural ventilation with the floor level in the studied classrooms, which was more manifested as the floor level increased upwards. In conclusion, the floor level and orientation affect wind-driven ventilation. There is also a need for further field studies on more suitable cases (higher floor levels) to ascertain the level of significance of this variation and the optimisation window area based on floor levels for orientation for wind-driven natural ventilation.

Development Strategy to Improve Class Classification In Nusantara Fishery Port Pengambengan, Bali Province

In the framework of improving governance, functional dimensions, and performance of the fishing port, the Nusantara Fishery Port in Jembrana Bali compiles a "strategic plan" to improve the class classification of the Nusantara Fishing Port Pengambengan to become a class A Ocean Fishing Port, a number of management facility criteria are required as the main prerequisites. The purpose of this study was to determine the condition of the facilities at Nusantara Fishing Port Pengambengan and to determine the strategy for developing a fishing port at Nusantara Fishing Port Pengambengan. This research method uses descriptive qualitative and quantitative methods. Data collection techniques through direct observation and interviews using a questionnaire regarding the condition of the facilities at Nusantara Fishing Port Pengambengan, then data analysis using a SWOT analysis approach. Nusantara Pengambengan Fishery Port is a class B port that functions as a support for the management and utilization of fish resources and the environment, starting from pre-production, production, processing and marketing of fishery products. In supporting fishery activities, Nusantara Fishing Port Pengambengan is currently supported by various facilities, namely basic facilities, functional facilities, and supporting facilities. The results showed that there were several facilities in poor conditions, namely basic pier facilities, anchoring ponds, complex roads, and drainage, from supporting facilities, namely public toilets and guest houses. Several facilities are not available in the Nusantara Fishing Port Pengambengan construction, namely ship docks, net repair wards/places, laboratories, WWTPs, watchtowers, and perimeter fences. The strategies obtained from the results of this study include: (1) Improving the quality of the catch to provide a positive image for potential investors. (2) Improve administrative services to provide fishermen comfort when carrying out fishing operations. (3) Support is needed, especially the role of the government related to management and development.

Watching Me, Watching You: Reflections Upon Surveillance, Gare Loch Duality and the #UndesiredLine

From my local observations, the everyday military surveillance, an ever-present panopticon, perpetuates both conscious and unconscious stress in the lives of those who endure it. In this paper I will reflect upon my experiences of a 224 mile pilgrimage that I undertook in 2018, over a period of 50 days. It was a daily walk from the front door of my house to the front door of the Faslane Nuclear Submarine Base, on the Gare Loch in Scotland. A walking performance, through which I drew an Undesired Line on the grass verge in parallel to an existing "undesired line" - the perimeter fence of the Base. Throughout the time the performance was in progress, I made an online text artwork using the Twitter hashtag #UndesiredLine. One year later, I reactivated the #UndesiredLine text-work in order to analyse subsequent observations and to establish a platform (and outlet) to examine the complex reality of Gare Loch ‘duality’. I will look at the potential legacy for The Undesired Line, and how I can use the documentation: video, photos, daily journal writings, field recordings, tweets and maps. In addition to appraising my own work, I will discuss surveillance focused artworks by David Rokeby, Janet Cardiff and The Surveillance Camera Players. I will also consider some of the ethical challenges of interactive art, as well as the implications and limitations of "piggy-backing" an online artwork onto existing online platforms such as Twitter and Google Maps.

Analysis of Expected Skin Burns from Accepted Process Flare Heat Radiation Levels to Public Passersby

Hot flaring, even from quite high flare stacks, may result in significant heat radiation outside a facility to, e.g., public roads where random passersby may be exposed. The present study suggests a novel method for analyzing a typical flare heat radiation exposure and investigates skin burns that may be inflicted on an exposed person if a facility needs to depressurize in an emergency situation. A typical radiation field from an ignited natural gas vent was taken as the boundary condition, and these values were compared to radiation levels mentioned by the American Petroleum Institute (API 521), e.g., 1.58 kW/m2 and above. Due to facility perimeter fences along roads in larger industry areas, it was assumed that an exposed person may flee along a road rather than in the ideal direction away from the flare. It was assumed that naked skin, e.g., a bare shoulder or a bald head is exposed. The Pennes bioheat equation was numerically solved for the skin layers while the person escapes along the road. Sun radiation and convective heat exchange to the ambient air were included, and the subsequent skin injury was calculated based on the temperature development in the basal layer. Parameters affecting burn severity, such as heat radiation, solar radiation, and convective heat transfer coefficient, were analyzed. For small flares and ignited small cold vents, no skin burn would be expected for 1.58 kW/m2 or 3.16 kW/m2 maximum heat radiation at the skin surface. However, higher flare rates corresponding to, e.g., 4.0 kW/m2 maximum flare heat radiation to the skin, resulted both in higher basal layer temperatures and longer exposure time, thus increasing the damage integral significantly. It is demonstrated that the novel approach works well. In future studies, it may, e.g., be extended to cover escape through partly shielded escape routes.

Towards generating a reliable device-specific identifier for IoT devices

A significant number of IoT devices are being deployed in the wild, mostly in remote locations and in untrusted conditions. This could include monitoring an electronic perimeter fence or a critical infrastructure such as telecom and power grids. Such applications rely on the fidelity of data reported from the IoT devices, and hence it is imperative to identify the trustworthiness of the remote device before taking decisions. Existing approaches use a secret key usually stored in volatile or non-volatile memory for creating an encrypted digital signature. However, these techniques are vulnerable to malicious attacks and have significant computation and energy overhead. This paper presents a novel device-specific identifier, IoT-ID that captures the device characteristics and can be used towards device identification. IoT-ID is based on physically unclonable functions (PUFs), that exploit variations in the manufacturing process to derive a unique fingerprint for integrated circuits. In this work, we design novel PUFs for Commercially Off the Shelf (COTS) components such as clock oscillators and ADC, to derive IoT-ID for a device. Hitherto, system component PUFs are invasive and rely on additional dedicated hardware circuitry to create a unique fingerprint. A highlight of our PUFs is doing away with special hardware. IoT-ID is non-invasive and can be invoked using simple software APIs running on COTS components. IoT-ID has the following key properties viz., constructability, real-time, uniqueness, and reproducibility, making them robust device-specific identifiers.We present detailed experimental results from our live deployment of 50 IoT devices running over a month. Our edge machine learning algorithm has 100% accuracy in uniquely identifying the 50 devices in our deployment and can run locally on the resource-constrained IoT device. We show the scalability of IoT-ID with the help of numerical analysis on 1000s of IoT devices. Further, we discuss approaches to evaluate and improve the reliability of the IoT-ID.11This manuscript is an extension of the paper ‘IoT-ID: A Novel Device-Specific Identifier Based on Unique Hardware Fingerprints’ Vaidya et al. (2020) published in 2020 IEEE/ACM Fifth International Conference on Internet-of-Things Design and Implementation (IoTDI).

Livestock Production Challenges and Improved Forage Production Efforts in the Damot Gale District of Wolaita Zone, Ethiopia

This study was conducted to identify major livestock production constraints and improved forage production efforts in the Damot Gale district. Four representative kebeles, two associated with our NGO project and two from nonproject outreach activities, were selected. Forty farmers from each kebele were randomly chosen for the purpose of individual interviews using a semistructured questionnaire. Data collected were analyzed using SPSS (version 20) and Excel. The topmost livestock production constraint was feed shortage where a larger proportion of farmers (75.6%) suffered from the problem with higher ( p ≤ 0.01) severity in nonproject intervention areas. Of these, 38.6% were challenged for a period of three months while another 61.4% suffered for about four months. Purchasing grass (31.4%) and concentrate (33.5%) and feeding enset (Ensete ventricosum) leaf (21.49%) were the most commonly adopted coping mechanisms to alleviate feed shortages during the dry season, while using purchased grass and enset leaf was the main coping strategy in nonproject intervention ( p ≤ 0.01) areas. The majority of households (90.75%) participate in improved forage production regardless of farm size. Desho grass (Pennisetum pedicellatum) (71.38%) and elephant grass (Pennisetum purpureum) (42.63%) are the most common improved forages in both study areas. These forages are produced for the purpose of two or more functions (feed, cash, and preventing erosion) that vary ( p ≤ 0.01) among intervention status. Major niche locations adopted for improved forage production include farm land, soil and water conservation structures, and perimeter fencing. Greatest constraints on improved forage production were seed/material shortage followed by land shortage and lack of awareness. Project intervention ( p ≤ 0.01), tropical livestock unit (TLU) holding ( p ≤ 0.01), and forage seed/planting material access ( p &lt; 0.05) were identified as factors (among others) having significant relationship with improved forage development. Strong extension services and efficient input delivery for farmers are vital to support profitable livestock production and resource utilization.

Environmental risk assessment in selected dumpsites in Abakaliki metropolis, Ebonyi state, southeastern Nigeria

Metal leaching into adjacent agricultural soil from dumpsites continues to hamper the quality of produce around the world. Three strategically located major solid waste Dumpsites within Abakaliki metropolis were selected and assessed for potential environmental risks of heavy metals. Samples of the soils from the dumpsites were collected from 0 to 15 cm and 15 to 30 cm soil depth. Multivariate approaches, descriptive statistics and contamination indices were employed. Metal concentrations were compared with local and international standard and most were found to be within the threshold. The results further showed that phosphate (PO43−), nitrate (NO3−) sulphate (SO42−), lead (Pb), copper (Cu), cadmium (Cd), zinc (Zn) and iron (Fe) varied within depths and across dumpsites. Metal concentration was generally higher at 0–15 cm depth and decreased at 15–30 cm. The distribution trend across the studied dumpsites was Fe > Zn > Cu > Pb > Cd. Anions (NO3−, PO43− and SO42−) concentrations generally increased with depth. We used the world average elemental concentrations as a benchmark for risk assessment. The factor of contamination (CF) and the environmental risk index (RI) indicated high contamination as well as environmental risks. The factor of enrichment (EF), Geo-accumulation index (Igeo) and modified environmental risk index (MRI) indicated very high enrichment and environmental risks of Pb, Cd, and Cu. Phyto-remediation, bioremediation, perimeter fencing, and periodic soil monitoring were recommended to restore the degraded soil for improved agricultural productivity.

Seasonal Activity and Diets of Bats at Uranium Mines and Adjacent Areas near the Grand Canyon

Little information exists on the habitat use and feeding ecology of insectivorous bats in arid ecosystems, especially at and near uranium mines in northern Arizona, within the Grand Canyon watershed. In 2015–2016, we conducted mist-netting, nightly acoustic monitoring (>1 year), and diet analyses of bats, as well as insect sampling, at 2 uranium mines (Pinenut and Arizona 1) with water containment ponds. Because of physical barriers and limited general access to areas within the mine yard, mist-netting was limited to outside of the perimeter fence and away from the containment ponds. Mist-netting also occurred at 2 nearby sites that served as proxies to the mines. Bats captured directly at the mines included one pregnant Antrozous pallidus and 3 adult male Parastrellus hesperus. At the proxy sites, we captured 45 individuals identified as A. pallidus, Corynorhinus townsendii, Eptesicus fuscus, Euderma maculatum, Lasionycteris noctivagans, Myotis californicus, Myotis ciliolabrum, P. hesperus, and Tadarida brasiliensis. The nightly and seasonal presence of bats, as shown through acoustic recordings at each mine, coincided with the seasonal migratory and hibernation behaviors of the bat species. Statistical comparisons of acoustic recordings with precipitation data collected over one year show that seasonal monsoon rains generally had a negative effect on the nightly activity and presence of bats. Diets of P. hesperus from both mines were comprised mostly of coleopterans but also included smaller volumes of Hymenoptera, Hemiptera, Lepidoptera, Diptera, and Neuroptera. The diet of A. pallidus was comprised solely of Coleoptera. Diets of bat species from the proxy sites were characteristic of their known feeding ecology, which ranged from the consumption of soft-bodied insects (e.g., moths) by C. townsendii to the consumption of hard-bodied insects (e.g., beetles) by E. fuscus. Ultimately, the increased knowledge of the natural history of bats through multiple methods of data collection allows for a better understanding of complex arid ecosystems. It also provides resources needed for the management of habitat associated with alternative energy, such as uranium mining.

Intentionally Overcharged?: R v Thacker &amp; Ors [2021] EWCA Crim 97

This is a case note on R v Thacker [2021] EWCA Crim 97 considering whether the trial judge had erred in convicting 15 activists who had breached an airport perimeter fence of intentionally disrupting services, contrary to the Aviation and Maritime Security Act 1990 s.1(2)(b). Issues discussed concern statutory interpretation, jury directions and the meaning of intent.

Biosecurity practices in commercial poultry farms located in ElFashir Locality- Sudan

This study was conducted to assess the biosecurity practices in commercial poultry farms in the locality of ElFashir, North Darfur State Sudan. Thirty two farms biosecurity tests were used, biosecurity practices were evaluated in poultry farms using the checklist and organized questionnaires administered to commercial poultry farmers. Simple descriptive statistics were used (frequencies and percentages) to summarize and display the results. The results showed that 62.5% of the farms used the floor brooding system of the birds; 59.4% open barns; The domestic stock in access to the farm site 68.8%; Pets or wildlife birds have access to inside of barns or feed storage 71.9%; yearly water quality is not checked by a reputable laboratory 96.9%; employees have routine contact with other poultry species 84.4%; regular cleaning and disinfection of feeders and drinkers washing is done mainly by soap in addition to water. 43.8%; employees and their families with other people on poultry housing site 100%; poultry production, feed consumption, and mortality records are kept, but not reviewed daily 18.8%; there is untrimmed vegetation and debris within barn(s) 81.2%; vehicle flow designated way traffic onto premises and off premises 100% and perimeter fencing and gate present but not always locked or guarded or fence not completed 56.25%. The study concluded that there is a severe weakness in the application of biosecurity practices in its three branches isolation, cleaning disinfecting and traffic control. The adopted hygiene and traffic control measurement were all within the high and medium biosecurity risk limits whereas mismanagement resembled 60.4% the highest risk of biosecurity practices among the studies in commercial poultry farms of ElFashir Locality. Therefore, it is strongly recommended for local authorities to intervene with qualified teams of poultry professional and experts to train poultry farmers, managers and attendees on importance of implementing sound biosecurity practices.

Intrusion behavior classification method applied in a perimeter security monitoring system.

A distributed optic fiber perimeter security system is proved to be an effective strategy for the security monitoring of some vital targets, such as power plants, power substations and telecommunication base stations. However, this method can hardly distinguish different categories of the intrusion behavior and is easily mis-triggered by different kinds of environmental interference. To distinguish different intrusion patterns and different interference events effectively, a vibration pattern recognition algorithm is proposed and demonstrated based on the merged Sagnac interferometer structure. The method consists of two parts: the pre-processing algorithm and the multi-layer perceptron neural networks (MLP-NNs). The pre-processing algorithm is applied to retrieve and extract the vibration signal from the captured source signal, and the MLP-NN is used to realize pattern recognition from each type of input. Typically, a high-dimensional vector group which contains hundreds of orders of vibration signal's power frequency is obtained to cover as many signalized features as possible. Moreover, results of the experiment deployed on a 10 kilometer long perimeter fence in the transformer substation show that the proposed classification-based model achieves 97.6% classification accuracy in the test. Through multiple comparison tests, the proposed model gives a solid performance in the subsequent integrated evaluation to classify each intrusion pattern.