The Livelihood Impacts of Resettlement Program, In Amhara Regional State, Ethiopia: A Propensity Score Matching Approach

This study examined the impact of resettlement program on the livelihood of the settlers in Jawie Woreda resettlement site among many resettlement programs conducted in Ethiopia. The study has an objective to evaluate livelihood impact of the resettlement program to the program participants using main livelihood indicator. The data obtained through structured questioner from rural households both from control group (who are remained back home) and treated group (who participate in the resettlement program). The stratified followed by simple random sampling technique used to select respondents. Using the propensity score matching particularly the stratified matching method, the counterfactual group has been constructed. The data was analysis by descriptive and inferential statistics among control and treated groups. Within major livelihood security indicator the result shows that participants have less mean livelihood security score on access to institution, shelter/water sanitation, health and gender status security index before matching but on average they are better than nonparticipants but the overall livelihood impact of the program has been estimated among matched sample which is the average treatment effect of the program on treated is 0.037 livelihood index. Specifically, on access to institution, shelter/water sanitation, and gender status security index the treatment effect of the program has negative effect so that treated groups are less advantageous in those major indicators compared to the non-treated group. Keywords: - Livelihood, Impact, and Resettlement DOI: 10.7176/RJFA/12-5-04 Publication date:March 31st 2021

A refined estimate for the topological degree

We sharpen an estimate of Bourgain, Brezis, and Nguyen for the topological degree of continuous maps from a sphere $\mathbb{S}^d$ into itself in the case $d \ge 2$. This provides the answer for $d \ge 2$ to a question raised by Brezis. The problem is still open for $d=1$

Perception of biological motion by jumping spiders

The body of most creatures is composed of interconnected joints. During motion, the spatial location of these joints changes, but they must maintain their distances to one another, effectively moving semirigidly. This pattern, termed “biological motion” in the literature, can be used as a visual cue, enabling many animals (including humans) to distinguish animate from inanimate objects. Crucially, even artificially created scrambled stimuli, with no recognizable structure but that maintains semirigid movement patterns, are perceived as animated. However, to date, biological motion perception has only been reported in vertebrates. Due to their highly developed visual system and complex visual behaviors, we investigated the capability of jumping spiders to discriminate biological from nonbiological motion using point-light display stimuli. These kinds of stimuli maintain motion information while being devoid of structure. By constraining spiders on a spherical treadmill, we simultaneously presented 2 point-light displays with specific dynamic traits and registered their preference by observing which pattern they turned toward. Spiders clearly demonstrated the ability to discriminate between biological motion and random stimuli, but curiously turned preferentially toward the latter. However, they showed no preference between biological and scrambled displays, results that match responses produced by vertebrates. Crucially, spiders turned toward the stimuli when these were only visible by the lateral eyes, evidence that this task may be eye specific. This represents the first demonstration of biological motion recognition in an invertebrate, posing crucial questions about the evolutionary history of this ability and complex visual processing in nonvertebrate systems

Physiological Costs of Repetitive Courtship Displays in Cockroaches Handicap Locomotor Performance

Courtship displays are typically thought to have evolved via female choice, whereby females select mates based on the characteristics of a display that is expected to honestly reflect some aspect of the male’s quality. Honesty is typically enforced by mechanistic costs and constraints that limit the level at which a display can be performed. It is becoming increasingly apparent that these costs may be energetic costs involved in the production of dynamic, often repetitive displays. A female attending to such a display may thus be assessing the physical fitness of a male as an index of his quality. Such assessment would provide information on his current physical quality as well as his ability to carry out other demanding activities, qualities with which a choosy female should want to provision her offspring. In the current study we use courtship interactions in the Cuban burrowing cockroach, Byrsotria fumigata to directly test whether courtship is associated with a signaler’s performance capacity. Males that had produced courtship displays achieved significantly lower speeds and distances in locomotor trials than non-courting control males. We also found that females mated more readily with males that produced a more vigorous display. Thus, males of this species have developed a strategy where they produce a demanding courtship display, while females choose males based on their ability to produce this display. Courtship displays in many taxa often involve dynamic repetitive actions and as such, signals of stamina in courtship may be more widespread than previously thought

Eight Legs And A Brain: Locomotor Mimicry Of Ants And Neuroethology Of Jumping Spiders

This thesis explores the ecology, behavior, and sensory neurobiology of jumping spiders (Araneae: Salticidae). The first section (Chapters 1 and 2) investigates antmimicry by the jumping spider Myrmarachne formicaria. The second section (Chapter 3) takes a neuroethological approach to sound perception in the jumping spider Phidippus audax. Chapter 1 uses observations and collections from sites across France to study the relationship between mimics and co-occurring ant species. Behavioral trials also explore how individual jumping spiders and ants interact. Results from these studies suggest that M. formicaria is a general mimic of multiple ant species and that it does not positively associate with ants. Chapter 2 takes a quantitative approach to the study of locomotor mimicry by M. formicaria. It measures and compares aspects of gait and overall movement across non-mimetic jumping spiders, mimics, and multiple ant species. Against widely held beliefs, this work suggests that these ant mimics do not move on six legs. In their overall motion, however, M. formicaria do imitate ants. Chapter 3 uses behavioral trials and extracellular recordings of electrical activity from neurons in the jumping spider brain to explore responses to airborne acoustic stimuli. This work demonstrates that jumping spiders perceive airborne sound at distances far greater than previously believed possible (> 2 m)

Diet influences mate choice selectivity in adult female wolf spiders

Most studies of female choice have assumed that mating preferences are shared within a population or species. However, variation both within and among females exists in natural populations, and foraging history is among the many ways in which females may vary. Here, we used diet manipulations in an effort to understand how foraging history influences female mate choice. Immature Schizocosa wolf spiders collected from a mixed population of brush-legged and non-ornamented males were reared in the laboratory on two diets that varied in both quality and quantity (low/high diet). For low- and high-diet individuals, we recorded data on rates of development, adult size and adult mate choice. Consistent with previous work, we found that high-diet spiders matured more quickly and were significantly larger as adults than low-diet spiders. Males also matured earlier than females. Body condition varied with diet treatment and sex. High-diet individuals and females were both characterized by better body condition indexes. In addition, high-diet brush-legged males had larger brushes than low-diet brush-legged males. Upon maturation, females were paired simultaneously with a low- and a high-diet male of the same form (brush-legged or non-ornamented) in a mate choice trial. While no obvious differences were observed in courtship and/or mating effort between males, female mate choice varied with the female’s diet treatment. High-diet females mated more frequently with high-diet males than with low-diet males, whereas low-diet females showed no selectivity