Proximity Feed Research Articles

Maternal Behavior in Sumatran Orangutans (Pongo abelii) is Modulated by Mother-Offspring Characteristics and Socioecological Factors

AbstractMammalian mothers flexibly invest in their offspring to maximize their lifetime fitness. Flexible maternal investment may be particularly important in large-brained species with prolonged maternal care, e.g., in great apes. We investigated the effects of socioecological factors and mother–offspring characteristics on nine maternal behaviors in wild Sumatran orangutans (Pongo abelii; N = 22 mother-offspring pairs; >11,200 hr of focal data from 2007–2022) using generalized linear mixed models. The behaviors fall under four maternal functions: locomotory support (carrying), skill acquisition support (feeding in proximity, food transfer), protective proximity maintenance (body contact and proximity initiation, following), and independence promotion (body contact and proximity termination, avoiding). Mother’s parity was not significantly associated with any maternal behavior. Mothers were more likely to show locomotory support, skill acquisition support, and protective proximity maintenance toward younger than older offspring, whereas they were more likely to promote independence in older than younger offspring. Mothers with male offspring were more likely to show skill acquisition support to their offspring than those with female offspring. With increasing food availability, skill acquisition support reduced. With increasing association size (i.e., the number of individuals within 50 m of each other), mothers were more likely to show protective proximity maintenance and less likely to promote independence. When males were present, mothers were more likely to show locomotory support to their offspring. Sumatran orangutan mothers thus flexibly adjust offspring-directed behavior in response to prevailing socioecological factors and mother–offspring characteristics. Our findings add support to the evolutionary theory that mammalian mothers flexibly invest in their offspring.

Endothelial Membrane Potential Changes are Required for Propagated Vasodilation

Introduction: The coordination of blood flow in response to localized increases in metabolic activity is vital for tissue function. This adaptive response typically involves the release of vasoactive factors leading to local vasodilation. This local vasodilation must propagate upstream to proximal feed arterioles and arteries to ensure a coordinated increase in blood flow and adequate tissue perfusion. But the mechanisms underlying such propagated vasodilation remain to be fully understood. This study aims to identify the conduction pathway(s) that facilitate this response. The hypothesis is that endothelial membrane potential changes are required for propagated vasodilation to occur. Methods: To dissect the pathways involved in propagated vasodilation, we employed micropuffng techniques to locally apply vasoactive agents to precontracted rat 2nd order mesenteric arteries. Using a 50um tip micropipette activators were applied against a flowing perfusate, to limit the action of the drug, and the precise site of activators determined by co-application of the fluorophore sulforhodamine. Vasodilator responses were recorded at the site of application and at intervals upstream from the application site. Results: Local application of the muscarinic receptor agonist, acetylcholine (ACh), evoked robust vasodilator responses that propagated upstream from the site of application. The propagation of vasodilation terminated at the site of removal of a 100uM wide strip of endothelial cells. A high-potassium solution, which induces depolarization and ‘clamps’ the membrane potential, also inhibited propagated vasodilation. In contrast, the nitric oxide donor, sodium nitroprusside did not initiate propagated vasodilation in arteries with an intact endothelium. Conclusion: Collectively, these results show that the endothelium serves as the primary signalling pathways for propagated vasodilation. Furthermore, our results highlight the necessity of endothelial cell membrane potential change in the initiation of this vasodilator signal. These insights reinforce the endothelium’s pivotal role in coordinating vascular function. British Heart Foundation. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A new analytical procedure to replace the outdated Weende proximal feed ingredient analysis paradigm is long overdue

A new analytical procedure to replace the outdated Weende proximal feed ingredient analysis paradigm is long overdue

PREVALENCE OF ANATOMICAL VARIATIONS OF CIRCLE OF WILLIS IN SOUTH INDIAN POPULATION SUCCUMBING TO ISOLATED TRAUMATIC BRAIN INJURY - A CADAVERIC STUDY

Introduction: The Circle of Willis (COW) is a large arterial anastomotic ring present at the basal cistern of the brain, uniting the internal carotid and the vertebro-basilar system. Sir Thomas Willis was the first to describe the importance of the circle in maintaining collateral flow. It was observed that there is very little mixing of blood between the collateral branches of the circle. These collaterals may however open up during occlusive episodes of the proximal feeding vessels or in case of severe stress such as stroke and traumatic brain injury (TBI) in order to maintain metabolic activity in the brain. This phenomenon is affected to various degrees in the presence of anomalies. The prevalence of anomalies of COW in the general population is up to 75.72% was demonstrated in other studies. Materials and Methodology: This is a cross sectional observational study. 20 consecutive patients above 18 years of age succumbed to isolated TBI who were subjected to medico-legal autopsy in our hospital were included. The anomalies were classified as per the criteria laid down by Stojanovi´c et al. Results: 9 Normal variants (Type A) of COW (45%) was found. The most common type of anomaly was Type C which was noted in 4 cases (20%). Conclusion: Anatomical variations of COW has proven association in the areas of stroke, aneurysm, migraine, carotid endarterectomy and ageing brains. Further studies are needed to determine whether the anomalies of COW really contribute to the mortality in TBI.

Smelling danger: Lady beetle odors affect aphid population abundance and feeding, but not movement between plants

Predator-prey interactions are complex ecological interactions that influence community structure and function. Predators affect prey density directly by consuming and removing prey from the environment. Additionally, predators can elicit non-consumptive effects in prey which influence prey survival by altering prey behavior and physiology. Key to understanding the consequences of non-consumptive effects for prey populations is determining mechanisms of detection of predation risk. With insects, olfactory cues are commonly used to convey information. It has been shown that insect prey may eavesdrop on predator odor cues as a means to determine predation risk. Herein, we assessed whether the volatile odors of the predatory insect Harmonia axyridis (multicolored Asian lady beetle) affect the behavior (feeding and dispersal behaviors) and performance (population abundance) of aphids (Myzus persicae). Aphids reduced phloem ingestion when feeding in close proximity to lady beetle cues, however, predator odors did not drive aphids to relocate on plants or to disperse across plants away from the odor source. The lack of dispersal we observed is in contrast to studies that show increased aphid movement in the presence of predators that can make physical contact with the aphids. We also found that lady beetle odor cues had a population-level effect on aphids, with 25% reduction in aphid population abundance in the presence of the odor cues. This study highlights that anti-predator strategies may differ depending on the mechanism of detection of predation risk (i.e. olfactory versus physical stimuli), or the context in which they experience them, and raises the question of whether anti-predator responses observed are maladaptive or beneficial to aphid survival. These conclusions are critical for both our basic understanding of the mechanisms driving predator-prey interactions as well as providing insight into pest-natural enemy interactions within agricultural landscapes.

Biochar yield prediction using response surface methodology: effect of fixed carbon and pyrolysis operating conditions

AbstractGenerating value from wastes via pyrolysis has been increasingly researched in recent times. Biochar is a versatile pyrolysis product with yields based on many process parameters, including feedstock type and particle size, and operating conditions such as pyrolysis reactor, heating rate, residence time, and reaction temperature. The heterogeneous nature of waste biomass creates challenges in controlling the pyrolysis’ product selectivity. Intensive and time-consuming experimental studies are often required to determine product distribution for the pyrolysis of each unique feedstock. Alternatively, prediction models that learn from a wide range of existing experimental data may provide insight into potential yields for different biomass sources. Several advanced models exist in the literature which can predict the yield of biochar and subsequent products based on operating temperature. However, these models do not consider the combined effect of biomass characteristics and operating conditions on biochar yield, which is considered a decisive factor for biochar formation. As such, the objective of this study is to develop a prediction model based on the biomass’ fixed carbon content (14–22%), reaction temperature (350–750 °C), and heating rate (5–10 °C/min) using the response surface methodology. Biomasses, date stones, spent coffee grounds, and cow manure have been used to design a Box-Behnken experiment based on the three factors for the biochar yield response. An empirical equation is developed based on a statistically significant quadratic model to produce optimized biochar yield with high prediction accuracy. The study discussed the 3D response and diagnostic plots and conducted validation experiments to confirm the applicability of the developed model. The biochar yields are significantly affected by the fixed carbon content of the feedstock and the reaction temperature, and the experimental validation confirms the accuracy of biochar yield quantification. The model can be easily applied for further process flow modeling of biomass pyrolysis, only relying on proximate feed analysis, operating temperature, and heating rate.

MUTUAL COUPLING REDUCTION IN STACKED STAR MIMO ANTENNA FOR WLAN AND ITU BAND APPLICATIONS

A two-port novel Stacked Star multiple-input multiple-output (MIMO) antenna with a physical size of 46 × 23 × 3.2 mm<sup>3</sup> is proposed. The proposed MIMO is designed for wireless communication applications such as Wireless Local Area Network (WLAN) and International Telecommunication Union (ITU) band resonating at 5.4 and 8.5 GHz, respectively. The Star is designed by using a basic circular antenna, from which Star geometry is constructed with iterations to obtain the desired frequency bands using Rogers RT5880 with a thickness of 1.6 mm for Stacked Star. The Stacked Star structure allows a wide bandwidth at the desired frequencies of 5.2-5.5 GHz and 8.2-8.6 GHz, respectively. To minimize mutual coupling, a T-slot stub is placed between the radiating patches. The proposed structures are simulated using Computer Simulation Technology. The proposed design is fed with proximity feed coupling for good impedance matching. Further, it provides an improved isolation of -8 dB. The important characteristics of the antenna such as reflection coefficients, Voltage Standing Wave Ratio, surface current distributions, and radiation patterns, are examined. In addition to that, MIMO characteristics elements like envelope correlation coefficient (ECC), and diversity gain (DG) and group delay -11.3 and -14.2 ns are investigated. The ECC is less than 0.01, while the DG is near 10 Db, indicating good MIMO performance. The anechoic measurement chamber and Schwarz ZVL vector network were used to measure the target MIMO antenna. The simulated and measured result shows a high degree of similarity so that the proposed antenna is strongly suggested for WLAN and ITU bands.

Feeding Behavior of Coralliophila sp. on Corals Affected by Caribbean Ciliate Infection (CCI): A New Possible Vector?

Coral reefs in the Caribbean are known to be affected by many coral diseases, yet the ecology and etiology of most diseases remain understudied. The Caribbean ciliate infection (CCI) caused by ciliates belonging to the genus Halofolliculina is a common disease on Caribbean reefs, with direct contact considered the most likely way through which the ciliates can be transmitted between infected and healthy colonies. Here we report an observation regarding a Coralliophila sp. snail feeding in proximity to a cluster of ciliates forming the typical disease band of CCI. The result of this observation is twofold. The feeding behavior of the snail may allow the passive attachment of ciliates on the body or shell of the snail resulting in indirect transport of the ciliates among colonies, which makes it eligible as a possible disease vector. Alternatively, the lesions created from snail feeding may enhance the progression of the ciliates already present on the coral as well as promoting additional infections allowing pathogens to enter through the feeding scar.

Comprehensive Study of Microstrip Patch Antenna Using Different Feeding Techniques

For modern wireless communication systems, miniaturized multiband antennas with enhanced bandwidth and gain are desired to achieve optimum system performance. A planar microstrip patch antenna is preferred because of its small size, low cost, and ease of fabrication. For impedance matching, a conductive metallic patch can be fed by different techniques to deliver the maximum power to the microstrip antenna. The various configurations of inset feed, co-axial feed, aperture feed, and proximity feed, and CPW feed, which are used to excite micro-strip patch antennas, are reviewed in this research paper. Different feeding mechanisms are discussed to improve antenna performance in terms of S11 parameter, bandwidth, gain, and radiation pattern suitable for different wireless communication applications.

Polarization-Agile Circular Polarized Antenna Based on Proximity Feeding Technique

In this letter, the design and experimental validation of polarization-agile circular polarized antenna are presented. The antenna is comprised of a patch antenna with truncated slits and two proximity feedlines. The antenna produces a vertical linear polarized wave when it is fed by a proximity feedline. Horizontal linear polarized wave is then generated by applying a potential difference between two proximity feedlines. The quadrature phase difference between two orthogonal polarized waves is created by adding truncated slits into the patch antenna. By swapping the polarity of the proximity feedlines, polarization sense can be changed. The distributed circuit model is presented to describe the working mechanism of the antenna. Patch antenna with circular polarization agility is then validated through passive-type and active-type switching circuits. The measured axial ratio bandwidth is 4.085% (100 MHz), and the fractional impedance bandwidth is greater than 7% for the left-handed and right-handed circular polarized radiations.

Management of Estradiol-Valerate and Dihydrotestosterone-Induced Benign Prostatic Hyperplasia in Mice Using <i>Zingiber Officinale</i> and <i>Musa Paradisiaca</i>-Incorporated Feed

Benign prostatic hyperplasia (BPH) is a disease condition with serious negative impact in the quality of life of elderly men. Detection of BPH is founded on lower urinary tract symptoms. This study investigated the efficacy of Zingiber officinale and Musa paradisiaca-incorporated diets in the management of hormonally-induced BPH. Twenty-four male Balb/c mice were distributed into six groups (n=4/group). BPH was induced through subcutaneous injection of 0.25 mg/kg/day of estradiol followed by 0.25 mg/kg/day of dihydrotestosterone for 14 days each. Non BPH-induced animals received equivalent volume of subcutaneous injection of olive oil for the same duration. BPH positive control group received standard mouse feed (Diet 1); drug control group received finasteride (5 mg/kg) orally, and Diet 1; test groups received 10% Z. officinale-incorporated feed (Diet 2), 50% M. paradisiaca-incorporated feed (Diet 3) and a feed blend containing 10% Z. officinale and 50% M. paradisiaca (Diet 4). Animals were fed exclusive study diets and were allowed access to water ad libitum. The proximate feed composition and BPH biomarkers were assayed using standard tests. Z. officinale contained higher levels of fats (9.36±0.28%) than M. paradisiaca (2.76±0.20%) whereas the latter showed higher carbohydrate content (70.44±0.2%) than the previous (60.37±0.5%). All test diets induced significant reduction (p 0.05) were recorded between the effects of diet 2 and 3. The results suggest that Z. officinale and M. paradisiaca-containing diets are effective for management of BPH. Z. officinale alone- incorporated diet is more effective than a mixture with M. paradisiaca. Supplementary longer duration studies using standardized feed preparations and exploring possible interactions between phytochemicals in the foodstuffs are essential to determine and understand lasting beneficial effects.

An Analysis of Slot Dimension Changing in Dual band Rectangular Patch Microstrip Antenna with Proximity Coupled Feed

In this paper, the characteristics of dual band rectangular patch microstrip antenna using proximity couple feed are studied. It can be used for a wireless device that works on multiband frequency. The addition of slot and proximity feed used in order to obtain larger bandwidth and multiple frequency. Microstrip antenna is designed and simulated using software also used to analyze by changing the variable of microstrip slot’s dimension. The parameters are tested in this study include Voltage standing wave ratio (VSWR), return loss, gain, bandwidth and radiation patterns. From the simulation results, the best value of return loss antenna is -23,29 dB at 2,4 GHz with a slot width of 1 mm and 0,085 GHz bandwidth. At 3,7 GHz, the best value of return loss antenna is -23dB with a slot width of 2 mm and 0,12 GHz bandwidth. Afterwards, the best VSWR obtained on dual band microstrip antennas with proximity coupled feed is 1,14 and 5.53 dBi gain.Keywords: slot, bandwidth, proximity, return loss, gain.

New simple low-cost surgical approach to complex jejuno-ileal atresia.

We report our experience of staged operations in the surgical treatment of complex jejuno-ileal atresia. Our study examined transgastric deflation of the proximal segment and feeding jejunostomy through the distal segment as a first stage followed by a definitive restoration of continuity secondarily at a tertiary centre over a period of three years. A cohort of 21 cases were studied. None suffered with intestinal perforation or volvulus. Tube plugging was seen in three patients who were relieved by flushing. Tube replacement was not required. One patient developed necrotising enterocolitis and died. Sepsis was seen in three. The age at the second operation was 56.2 ± 6.6 days. There was no complication after this second procedure. We therefore recommend this staged management for complex jejuno-ileal atresia, but suggest further studies.

Dynamic enhanced proximity coupling technique for antennas

Role of feeding is very important for the efficient operation of an antenna. Changes in the feeding structures improve (i) bandwidth (BW), (ii) return loss and (iii) impedance matching (IM). Common coaxial feeding produces low return loss and good IM, but it yields narrow BW. Proximity feeding increases BW and eliminates spurious radiation at the cost of high losses. Dynamic feeding attains low losses, good IM and narrow BW along with frequency reconfiguration (FR). This paper aims to produce broad BW and FR antenna with the help of Dynamic Enhanced Proximity Coupling (DEPC) technique. In this, a multiple substrate layer antenna with a patch in one layer and feed in another layer along with ascension of feed position produces a low loss, broad BW and FR antenna. The DEPC design, which is tested on rectangular patch and fractal structures, achieves improved current distribution and overall BW compared to other techniques.

Optimization of Directivity and Gain Performances on Circular Patch Antenna Design for 2.4 GHz Applications

In this paper, simulation and optimization analysis on circular patch antenna for 2.4GHz is presented. The performance that been specifically focused in this analysis is the improvement of the directivity and gain of the circular patch antenna design. Basically, the objective of this analysis is to compare the circular patch antenna of a single form with 1x2 antenna array formation. These antennas are designed with the proximity feeding technique. From the previous literature and findings, the optimization works of array arrangement have been proven will improve the directivity and gain performances. In this study, the array arrangement with proximity feeding technique of optimization work to improve the directivity and gain of a circular patch antenna has been explored. Comparison of a single and array of micro strip circular patch with proximity feeding technique as the FR-4 is the substrates with permittivity equal to 3.95 is presented. Based on the results, 1x2 array arrangements enhance the directivity and gain output compared to a single form circular patch antenna design. The directivity performance improves 28% and gain has been improved by 47% after optimization. The findings show that the array elements with proximity feeding technique design offer to improve and enhance the directivity and gain performances of an antenna.

Integrated circular polarized microstrip antenna with dual‐mode‐polarization insensitive characteristics

A dual-mode circularly polarized compact antenna with integrated left-hand and right-hand circular polarization (LHCP and RHCP) is presented in this work. A multilayer arrangement of a square patch and square ring structure with an irregular transmission line is analyzed for dual-band, dual-CP operation. To realize dual mode propagation the proposed structure is excited using electromagnetic coupling technique. Succeeding proximity feeding with T-stub match is analyzed, which conveys impedance bandwidth of 180 and 300 MHz within |S11| < −10 dB at 3.5 and 5.5 GHz. The designed CP elements is suitably arranged with feed line for generating two orthogonal polarization of equal amplitude and a 90° phase difference at both the resonant modes (TM10 and TM01). Alterable LHCP and RHCP performance is realized by altering the compensated position and peculiar angle. Having both LHCP and RHCP polarization this design shows polarization insensitive characteristic. Each LHCP and RHCP antenna element accomplished a 3-dB AR of 70 and 120 MHz with a gain up to 6 dBi. With a low profile of 0.27λ0 × 0.27λ0 × 0.04λ0, the CP antenna is fabricated, and the performance is validated through experimental analysis. With all the viable characteristics, the antenna is proposed for Wi-MAX/WLAN communication.

Incorporating tick feeding behaviour into [formula omitted] for tick-borne pathogens

Tick-borne pathogens pose a considerable disease burden in Europe and North America, where increasing numbers of human cases and the emergence of new tick-borne pathogens has renewed interest in resolving the mechanisms underpinning their geographical distribution and abundance. For Borrelia burgdorferi and tick-borne encephalitis (TBE) virus, transmission of infection from one generation of ticks to another occurs when older nymphal ticks infect younger larval ticks feeding on the same host, either indirectly via systemic infection of the vertebrate host or directly when feeding in close proximity. Here, expressions for the basic reproduction number, R0, and the related tick type-reproduction number, T, are derived that account for the observation that larval and nymphal ticks tend to aggregate on the same minority of hosts, a tick feeding behaviour known as co-aggregation. The pattern of tick blood meals is represented as a directed, acyclic, bipartite contact network, with individual vertebrate hosts having in-degree, kin, and out-degree, kout, that respectively represent cumulative counts of nymphal and larval ticks fed over the lifetime of the host. The in- and out-degree are not independent when co-aggregation occurs such that T∝〈kinkout〉〈kin〉,where 〈.〉 indicates expected value. When systemic infection in the vertebrate host is the dominant transmission route R02=T, whereas when direct transmission between ticks co-feeding on the same host is dominant then R0=T and the effect of co-aggregation on R0 is more pronounced. Simulations of B. burgdorferi and TBE virus transmission on theoretical tick-mouse contact networks revealed that aggregation and co-aggregation have a synergistic effect on R0 and T, that co-aggregation always increases R0 and T, and that aggregation only increases R0 and T when larvae and nymphs also co-aggregate. Co-aggregation has the greatest absolute effect on R0 and T when the mean larval burden of hosts is high, and the largest relative effect on R0 for pathogens sustained by co-feeding transmission, e.g. TBE virus in Europe, compared with those predominantly spread by systemic infection, e.g. B. burgdorferi. For both pathogens, though, co-aggregation increases the mean number of ticks infected per infectious tick, T, and so too the likelihood of pathogen persistence.

Series-Fed Dual-Polarized Single-Layer Linear Patch Array With High Polarization Purity

In this letter, a novel dual-polarized 1 × 4 patch array using proximity feed technique is presented. The proposed single-layer antenna consists of four square patch elements, two short-terminated parallel coupled microstrip lines, and a rat-race incorporated in the feed network. The patches are placed at the inner space between the two parallel microstrip feedlines. Horizontal and vertical polarizations of the patch array are excited by the even and odd modes of the two microstrip lines, respectively. The rat-race structure is used to provide in-phase and 180° out-of-phase feeds for the two modes. A prototype operating at 3.5 GHz is fabricated and measured. The measured overlapping bandwidth of the two ports is 81 MHz, also with port isolation higher than 40 dB. Owing to the symmetry of the structure and balanced excitations, the measured cross polarizations are all below -29 dB in E- and H-planes.

Direct and electromagnetically coupled compact microstrip antenna design with modified fractal DGS

This article proposes ultra-miniature microstrip patches with direct and electromagnetically coupled feeding mechanism for wireless communications at 10 GHz. Antenna size reduction is achieved here by loading a modified Minkowski fractal (type-2) defected ground structure (MFDGS-II) exactly beneath the radiating patch. The proposed method involves the selection of best DGS configuration through sensitivity analysis of the antenna structure. From different applications point of view, three different designs: a single layer direct fed patch and two electromagnetically coupled fed multi-layered microstrip patch antennas are proposed here and designed with MFDGS-II. The resonant frequencies of the antenna designs are reduced in a significant manner incorporating MFDGS-II without any change in the physical size of the antenna. The prototypes of the proposed antennas are fabricated, and the performance parameters are measured. Compared with other existing structures, with a lower patch size of 0.20 λ0 × 0.15 λ0, the proposed single layered antenna with microstrip feed achieves a patch size reduction up to 67% and an overall volumetric reduction of 84%, respectively. Similarly, the proposed multi-layered patch with proximity feed exhibits a maximum impedance bandwidth of 600 MHz and the aperture coupled fed patch has a realized gain of 6.2 dBi with radiation efficiency of 91% centered at 10 GHz. All three proposed compact antenna structures are best in three different aspects and have the potential to meet the practical requirements for X-band portable wireless applications.

What influences a pet dog's first impression of a stranger?

Dogs live in the dynamic human social networks full of strangers, yet they form strong and selective bonds with familiar caretakers. Little is known about how a bond is initially formed between a dog and a complete stranger. The first-impression hypothesis suggests that interacting with strangers can present an opportunity to form a mutualistic partnership. It predicts that dogs should respond positively toward a complete stranger to facilitate bonding (Prediction 1) and adjust their preferences in response to the perceived risk and benefit of interacting with strangers (Prediction 2). We examine the social preferences of pet dogs toward a complete stranger whom they have never met before and several other potential partners - the owner with whom subjects have had a positive, long-term bond (Experiment 1), and an exposed stranger with whom they have had a positive short-term interaction (Experiment 2) or a negative one (Experiment 3). In support of Prediction 1, subjects were exceptionally trusting across contexts. Mixed results were found with regard to Prediction 2. Subjects preferred their owner over a stranger when following social cues and (to a lesser degree) when approaching and feeding in close proximity. However, relative to a complete stranger, subjects did not consistently prefer the positively exposed stranger or avoid the negatively exposed one. The lack of clear selectivity might be due to pet dogs' high baseline level of trust of complete strangers or reflect the strength of their existing bonds that negated the need for another positive bond with a new human partner.