This paper presents the design and analysis of a compact eight-port multiband multiple-input–multiple-output (MIMO) antenna for 5G smartphones. The proposed antenna structure is designed using meandering elements, as radiator, on the FR4 substrate of 150 × 80 × 0.8 mm with loss tangent (tan δ) of 0.02 and relative permittivity (εr) of 4.4. The proposed antenna resonates at 2.4, 3.5, and 5.5 GHz, and it covers the bandwidth of 2%, 6.28%, and 2.53%, respectively. The measured results provide an omnidirectional radiation pattern with 58%–78% of efficiency in all operating bands. The eight-port multiband MIMO design provides a high isolation of 17.5 dB, envelope correlation coefficient < 0.04, diversity gain of 9.98 dB, total active reflection coefficient < −10 dB, and channel capacity loss of <0.25 bits/s/Hz. Also, the hand phantom is designed to analyze the reflection coefficients and efficiency of the proposed antenna.

Palmer amaranth (Amaranthus palmeri S. Watson), a dioecious wind-pollinated plant, is one of the most troublesome crop weeds in the United States and is spreading northward. The prodigious production of seed contributes to establishment of populations and spread across the landscape. Sexual reproduction via outcrossing is likely the primary mode of seed production for this dioecious plant. However, A. palmeri may also be capable of autonomous asexual seed production (apomixis), which could be beneficial during colonization. We conducted two studies of female isolation from pollen to investigate the propensity for autonomous seed production in 19 populations across eastern North America. In the first, we observed low-frequency seed production on many isolated females. Using flow cytometry of seed samples (FCSS) we primarily found patterns of ploidy consistent with sexual reproduction; no significant differences in ploidy between seeds produced on isolated females (putative apomicts) and non-isolated females (putatively sexual) were detected. We also investigated patterns of DNA content and found no evidence in 153 samples for polyploidy, which is often observed in apomictic species. The second female isolation trial utilized sex-specific molecular markers to identify and remove males before flowering, and we observed zero seed production. Overall, we did not detect evidence in support of apomixis in these populations of A. palmeri, suggesting that apomixis is unlikely to have played a role in the northward advance of this species in eastern North America. We also investigated whether there is variation between females and males in size and secondary reproductive traits. We found evidence for sexual dimorphism in three of six traits investigated: females are taller at senescence and produce longer secondary branches and more axillary flowers than males. Differences in cost of reproduction and strategies for pollen release versus pollen capture are likely factors shaping the evolution of sexual dimorphism in this wind-pollinated dioecious plant.

We examine the use of forced confinement and isolation to limit the spread of COVID-19 in Ontario prisons and jails. Drawing on interview data, we illustrate how a reliance on forced confinement and isolation has exacerbated harms experienced by prisoners in relation to physical, mental, and social health. Through discourse analysis of grey literature, we then discuss the politics and governance of carceral institutions during the pandemic, focusing on how practices of isolation were legitimized during the pandemic, despite recent rulings establishing isolation and segregation as torture. We close by arguing that the case of isolation during the pandemic is one example which highlights the systemic and ongoing nature of rights violations in Canadian prisons and jails. To address these harms, we must shift focus away from reform and towards decarceration.

This communication presents the significance of a four-port 2×2 multiple input multiple output antenna operating in mid-band frequency for 5G handheld device application. A microstrip-fed reference truncated decagonal monopole antenna operating at 3.9 GHz and a modified split-ring resonator (SRR)-based low-pass filter that excites at a cut-off frequency of 6.5 GHz are designed. On introducing a stub line in the SRR structure, the proposed filter shows a good out-of-band rejection beyond 6.5 GHz. By integrating the filter into the reference monopole, a wideband filtering monopole with improved stopband performance is obtained. A four-port MIMO array is constructed by orthogonally positioning the antenna with a center-to-center separation of 0.25λ0. To improve isolation, a pair of inverted L-stubs of varying lengths is introduced. The closed loop formed by the interconnection of stubs enhances isolation within the frequency range of 3–3.5 GHz. The fabricated prototype fosters an impedance bandwidth of 66.67%, isolation >18.5 dB, an average suppression of 15 dB, an average peak gain >3.7 dB, envelope correlation coefficient < 0.015, Actual Diversity Gain (ADG) > 9.9 dB, Effective Diversity Gain (EDG) > 8.8 dB, and efficiency >88%. The proposed design is suitable for 5G sub-6 GHz applications such as n48, n77, n78, n79 bands, WiMAX, and LTE bands 42, 43, 46, 47, 48.

The Atlantic Forest of South America has undergone major changes due to urban and agriculture/pasture extension, resulting in a highly fragmented biome. Protected areas, created to ensure the biodiversity conservation of this biome, need to be connected for long-term landscape integrity. We aimed to quantify connectivity among protected areas in the south-east Atlantic Forest using two species with different environmental requirements: a threatened species with high requirements, the jaguar Panthera onca; and an exotic species with low requirements, the wild pig Sus scrofa. Our methods included expert opinion, and Circuitscape and least-cost-path analyses. We hypothesized that the patchy and altered landscape would not support the connectivity of jaguars but would allow wild pigs to transit. In fact, we found connectivity for both species, but there were more connectivity opportunities for wild pigs. The connection between Serra do Mar (and Serra do Mar state park) and Serra da Mantiqueira (Mantiqueira Mosaic) is narrow but possible to traverse through some protected areas of sustainable use and private reserves, highlighting the importance of these to structural landscape connectivity for the studied species in this region. The same connectivity that allows the transit of the native jaguar with high environmental requirements also allows the invasive wild pig to move through the landscape, which is worrisome.

Female laboratory rats (Rattus norvegicus; Wistar, Alderley Park) were housed as singletons or groups of three in units of two cages. Units were divided by different types of barrier which allowed varying degrees of social contact across the barrier. Singletons were established either with another singleton on the other side of the barrier or with a group of three as neighbours. Single-housing among females had markedly less effect on time budgeting and pathophysiological measures than among males in a similar, earlier study. In particular, singletons showed a less marked increase in self-directed behaviours, particularly tail chasing, and a smaller reduction in undirected movement around the cage. The smaller reduction in mobility may reflect a greater tendency for singly housed females to attempt escape. Females generally showed much higher levels of escape-oriented behaviours than males and up to a threefold increase in such behaviours when housed singly. Differences in time budgeting and in the apparent significance of social separation between the sexes can be interpreted in terms of differences in socio-sexual strategy and potential mating opportunity, with singleton males responding to their cage as a territory, but singleton females seeking to re-establish social contact. Such an interpretation is consistent with the effects of barrier type on behaviour in singleton females, in which time spent in escape-oriented behaviours reflected the extent to which the barrier facilitated, or frustrated, contact with neighbours.

Male laboratory rats (Rattus norvegicus; Wistar, Alderley Park) were housed as singletons or groups of three in units of two joined, but divided cages. Units were divided by different types of barrier that allowed different degrees of social contact across the barrier. Singletons were established either with another singleton as a neighbour on the other side of the barrier, or with a group of three as neighbours. Relative to group-housed animals, singly-housed rats showed reduced activity and a greater incidence of self-directed behaviours and behaviours apparently related to escape or seeking social information. Pathophysiological evidence was consistent with Baenninger's (1967) suggestion that tail manipulation in singletons is a surrogate social response, but was also consistent with an overall increase in self-directed activity, reflecting elasticity in time budgeting. Variation in the degree of increase in self-directed activity among singletons and the negative correlation between self-directed activity and organ pathology may have reflected differences in the ability of individuals to avoid an activity limbo. While reduced corticosterone concentration and organ pathology compared with grouped rats implied that separation may remove social stress, responses to contact with neighbours, and correlations between behaviours and organ pathology suggested that rats may actively seek social interaction. Broad differences in stress responses between single and grouped housing conditions may therefore be an inadequate yardstick to the animals’ welfare. However, exposure to neighbours reduced the aggressiveness of singly-housed males when they were eventually introduced into an unfamiliar group, suggesting that a degree of exposure to neighbours (separation, but not isolation) may have some welfare benefits for laboratory-housed rats, depending on procedures.

The present study examines the plasma cortisol reaction of suckling and non-suckling calves and their dams to short-term emotional stressors. Twenty six cow-calf pairs were randomly allocated into one of two treatments: restricted suckling (R) or artificially milk-fed (A). On the day of weaning, blood samples were taken to determine the basal cortisol level in the calves' home-pen. Immediately, calves from both groups were moved to an unfamiliar surrounding and isolated. After sampling cows were then moved to a trimming pen, and restrained for three hours. Higher cortisol concentrations were found in A-calves in comparison with R-calves starting 90 min post-isolation through until the end of the experiment (90 min later). A significant increase was detected 60 min post-isolation in A-calves, with highest values averaging 29.22 ± 7.27 ng ml–1, decreasing to basal levels 130 min later. In cows, no difference in serum cortisol concentration was found either between treatments or over time. It was concluded that calves allowed to suckle react to a short-term emotional stressor with less plasma cortisol concentration than artificially reared calves.

Mirrors can enrich the environment of some social animals kept in isolation. In this study, the effect of mirrors on the behaviour of isolated, or partially isolated, caged rabbits was tested. In a changeover experiment, four treatments were investigated: isolated without mirrors; partially isolated (with a conspecific housed behind a partition) without mirrors; isolated with mirrors; and partially isolated with mirrors. Behaviour was recorded during the first hour for which the rabbits were in the cages with the stimuli, and then again after one week. Initially, the rabbits' alertness increased, which may be because they perceived the mirror image to be a potential threat. The mirrors also stimulated investigation by the rabbits, which initially scraped them rapidly with their forepaws (scrabbling) and sniffed them. Although sniffing was maintained until the end of the week, scrabbling was not, probably because the rabbits failed to elicit the normal reactions of a conspecific from their mirror images. Mirrors also reduced the time rabbits spent sitting in their living area looking out of the cage, and increased their behavioural complexity, as determined from the number of behaviours performed per minute. In a second experiment, the responses of seven rabbits to four stimuli were recorded: a conspecific; a toy animal; a mirror; and a blank card. The rabbits were presented with pairs of stimuli at either end of a marked board. The responses of the rabbits to mirrors were more similar to their responses to a blank card or to a soft toy than to a conspecific. Although the rabbits did not respond to mirror images as if they were conspecifics, the mirrors may have had benefits to the complexity of behaviour of rabbits in small cages.

Isolating an animal refers to the situation where the animal is physically fully demarcated from conspecifics without physical, visual, olfactory and auditory contact. Animals housed in separate cages in the same room are, although deprived of physical and visual contact, still in olfactory and auditory contact, and thus not totally isolated. During the fifties and sixties several studies claimed to show physiological and behavioural differences between individually and group housed rats and mice. The so-called ‘Isolation Syndrome’ characterised by changes in corticosterone levels, metabolism, growth, and behaviour was introduced, rather as a model for psychoneurosis than through any concern for animal welfare. Today, it is often stated as common knowledge in laboratory animal science textbooks that individual housing as well as isolation of rats and mice has an effect on physiology and behaviour. It is, however, unclear whether this effect actually impairs animal welfare.

The aim of this paper is to analyse studies on individual housing of mice and rats to evaluate whether there is documented proof that individual housing affects welfare, and, alternatively whether it is possible to house these animals individually without negative impact on welfare, eg by providing special housing improvements.

A range of studies have shown that individual housing or isolation has effects on corticosterone, the open field behaviour, barbiturate sleeping time and the metabolism of different pharmaceuticals in the animals. However, this review of 37 studies in rats and 17 studies in mice showed divergence in test results difficult to explain, as many studies lacked basal information about the study, eg information on genetic strains and housing conditions, such as bedding, enrichment and cage sizes. Furthermore, test and control groups most frequently differed in cage sizes and stocking densities, and behavioural tests differed in ways which may very well explain the differences in results. Overall, there seemed to be an effect of individual housing, although it may be small, and it seems reasonable to assume that, through making small changes in the procedures and housing environments, the effects can be minimised or even eliminated. More well-controlled and standardised studies are needed to give more specific answers to the questions this issue poses.