Hereditary Angioedema Attacks Resolve Faster and Are Shorter after Early Icatibant Treatment

Background

Attacks of hereditary angioedema (HAE) are unpredictable and, if affecting the upper airway, can be lethal. Icatibant is used for physician- or patient self-administered symptomatic treatment of HAE attacks in adults. Its mode of action includes disruption of the bradykinin pathway via blockade of the bradykinin B₂ receptor. Early treatment is believed to shorten attack duration and prevent severe outcomes; however, evidence to support these benefits is lacking.

Objective

To examine the impact of timing of icatibant administration on the duration and resolution of HAE type I and II attacks.

Methods

The Icatibant Outcome Survey is an international, prospective, observational study for patients treated with icatibant. Data on timings and outcomes of icatibant treatment for HAE attacks were collected between July 2009–February 2012. A mixed-model of repeated measures was performed for 426 attacks in 136 HAE type I and II patients.

Results

Attack duration was significantly shorter in patients treated <1 hour of attack onset compared with those treated ≥1 hour (6.1 hours versus 16.8 hours [p<0.001]). Similar significant effects were observed for <2 hours versus ≥2 hours (7.2 hours versus 20.2 hours [p<0.001]) and <5 hours versus ≥5 hours (8.0 hours versus 23.5 hours [p<0.001]). Treatment within 1 hour of attack onset also significantly reduced time to attack resolution (5.8 hours versus 8.8 hours [p<0.05]). Self-administrators were more likely to treat early and experience shorter attacks than those treated by a healthcare professional.

Conclusion

Early blockade of the bradykinin B₂ receptor with icatibant, particularly within the first hour of attack onset, significantly reduced attack duration and time to attack resolution.     

Childhood Internalizing and Externalizing Problems Predict the Onset of Clinical Panic Attacks over Adolescence: The TRAILS Study

Background

Panic attacks are a source of individual suffering and are an independent risk factor for later psychopathology. However, much less is known about risk factors for the development of panic attacks, particularly during adolescence when the incidence of panic attacks increases dramatically. We examined whether internalizing and externalizing problems in childhood predict the onset of panic attacks in adolescence.

Method

This study is part of the TRacking Adolescents’ Individual Lives Survey (TRAILS), a Dutch longitudinal population cohort study (N = 1,584). Internalizing and Externalizing Problems were collected using the Youth Self-Report (YSR) and the parent-report Child Behavior Checklist (CBCL) at baseline (age 10–12). At age 18–20, DSM-IV defined panic attacks since baseline were assessed with the Composite International Diagnostic Interview (CIDI). We investigated whether early adolescent Internalizing and Externalizing Problems predicted panic attacks between ages 10–20 years, using survival analysis in univariate and multivariate models.

Results

There were N = 314 (19.8%) cases who experienced at least one DSM-IV defined panic attack during adolescence and N = 18 (1.2%) who developed panic disorder during adolescence. In univariate analyses, CBCL Total Problems, Internalizing Problems and three of the eight syndrome scales predicted panic attack onset, while on the YSR all broad-band problem scales and each narrow-band syndrome scale predicted panic attack onset. In multivariate analyses, CBCL Social Problems (HR 1.19, p<.05), and YSR Thought Problems (HR 1.15, p<.05) and Social Problems (HR 1.26, p<.01) predicted panic attack onset.

Conclusion

Risk indicators of panic attack include the wide range of internalizing and externalizing problems. Yet, when adjusted for co-occurring problem behaviors, Social Problems were the most consistent risk factor for panic attack onsets in adolescence.     

Dead or Alive? Factors Affecting the Survival of Victims during Attacks by Saltwater Crocodiles (Crocodylus porosus) in Australia

Conflicts between humans and crocodilians are a widespread conservation challenge and the number of crocodile attacks is increasing worldwide. We identified the factors that most effectively decide whether a victim is injured or killed in a crocodile attack by fitting generalized linear models to a 42-year dataset of 87 attacks (27 fatal and 60 non-fatal) by saltwater crocodiles (Crocodylus porosus) in Australia. The models showed that the most influential factors were the difference in body mass between crocodile and victim, and the position of victim in relation to the water at the time of an attack. In-water position (for diving, swimming, and wading) had a higher risk than on-water (boating) or on-land (fishing, and hunting near the water''s edge) positions. In the in-water position a 75 kg person would have a relatively high probability of survival (0.81) if attacked by a 300 cm crocodile, but the probability becomes much lower (0.17) with a 400 cm crocodile. If attacked by a crocodile larger than 450 cm, the survival probability would be extremely low (<0.05) regardless of the victim’s size. These results indicate that the main cause of death during a crocodile attack is drowning and larger crocodiles can drag a victim more easily into deeper water. A higher risk associated with a larger crocodile in relation to victim’s size is highlighted by children’s vulnerability to fatal attacks. Since the first recently recorded fatal attack involving a child in 2006, six out of nine fatal attacks (66.7%) involved children, and the average body size of crocodiles responsible for these fatal attacks was considerably smaller (384 cm, 223 kg) than that of crocodiles that killed adults (450 cm, 324 kg) during the same period (2006–2014). These results suggest that culling programs targeting larger crocodiles may not be an effective management option to improve safety for children.     

The time course of attack priming effects in female golden hamsters

In two experiments using different procedures we have found that attack latency, having been reduced by a previous priming attack, returns to baseline levels over a 24 hr period. In both experiments an unexpected, transient increase in attack latency occured 2 hr postpriming. The procedure of the second experiment precludes the possibility that this is a circadian effect. There were no cumulative effects of successive priming attacks suggesting that, under the conditions of these experiments, each attack “resets” the animals' aggressive state. The effects of a single brief agonistic encounter are substantial and persistent enough to be involved in such phenomena as the escalation and redirection of aggression observed in field studies.     

Chemical (VX) terrorist threat: public knowledge, attitudes, and responses

This article reports the results of a study of people's perceptions and reactions to a hypothetical terrorist attack involving a chemical agent (specifically, the nerve agent VX). Thirteen focus groups composed of 8 to 12 participants each were conducted using trained moderators. To achieve a broad representation of perspectives, the groups were conducted in several regions and included urban and rural locations. In addition, a variety of population groups, such as African Americans, Hispanics, American Indians, Asians, and people with English as a second language, were included in the study. Findings demonstrated fear, fatalism, and unfulfilled information needs related to the threat agent. To better prepare the public for VX threats or threats from other highly toxic chemical agents, it will be important to emphasize that VX exposure can be avoided or reduced, that VX effects can be treated, and that VX can be survived if appropriate protective measures are taken. Related findings from the focus groups are that participants preferred television, radio, and the Emergency Alert System for emergency messages and that people prefer to hear information about a chemical attack from a well-known, well-respected public figure or from a content expert on chemical attacks, protective actions, and health. In addition, local television meteorologists were identified as a category of trusted conveyers of important information in relation to chemical terrorist attacks.     

The Weight of Cognitions in Panic: The Link between Misinterpretations and Panic Attacks

In cognitive theory it is hypothesized that panic attacks are provoked by catastrophic misinterpretations of bodily sensations. The aim of the present study was to investigate the ability of associated word pairs referring to catastrophic thinking (e.g. palpitations-heart attack) in producing panic attacks. Patients with PD (n = 20), patients with mixed anxiety disorders (n = 20), and a healthy control group (n = 30) participated in the present study. To enhance ecological validity we first conducted a stimulus validation experiment. Subsequently, nine suitable panic and neutral word pairs were presented in block to the participants. Anxiety levels were assessed before and after the presentation. PD patients were more anxious when reading these word pairs, compared to neutral word pairs. However, none of the participants experienced a panic attack upon reading the word pairs. From the present results it seems that catastrophic thinking is rather related to the anticipatory anxiety for panic attacks, but not necessarily with the occurrence of the panic attacks themselves.     

Challenges of Large Carnivore Conservation: Sloth Bear Attacks in Sri Lanka

Sloth bear (Melursus ursinus) attacks in Sri Lanka present a major challenge to their conservation as human populations grow and compete with bears for space and resources. Bear attacks on humans predominantly affect the rural poor and seem to be increasing in frequency. In 2004, we conducted the first island-wide survey of bear attacks in Sri Lanka. Our main goals were to 1) describe where and when attacks occurred, 2) describe the characteristics and outcome of bear attacks, and 3) evaluate the influence of human group size on the severity of bear attacks. We interviewed 271 individuals attacked by sloth bears between 1938 and 2004. Sloth bears rarely entered village compounds, damaged property, or raided crops; conflicts predominantly involved attacks on people in forests. Most sloth bear attacks took place during daylight hours (0900-1600 h) in the dry season, when humans were likely to engage in forest activities such as honey gathering. Most attacks (80 %) occurred when humans and bears surprised each other at close proximity (<10 m). Most (84 %) victims carried a weapon but 55 % said the attack was too sudden to effectively use the weapon in self-defense. Human injuries included lacerations and puncture wounds, broken limbs, skull fractures, and the loss of scalps, eyes, or other parts of the face. Almost all major injuries resulted from bites. In 61 attacks bears were wounded and in 39 attacks bears were killed. The severity of human injuries depended on human group size; solitary humans experienced more severe injuries than expected, suggesting that the presence of other humans may moderate the bear’s aggression and motivate it to flee. Widespread fear of sloth bears poses a significant challenge to modifying ineffective human responses to bear encounters (e.g., fleeing). Conservation outreach could emphasize that greater human safety may be achieved from remaining in groups and using extreme caution around thickets and rock outcrops likely to be used by bears.     

The temporal selfish herd: predation risk while aggregations form

The hypothesis of the selfish herd has been highly influential to our understanding of animal aggregation. Various movement strategies have been proposed by which individuals might aggregate to form a selfish herd as a defence against predation, but although the spatial benefits of these strategies have been extensively studied, little attention has been paid to the importance of predator attacks that occur while the aggregation is forming. We investigate the success of mutant aggregation strategies invading populations of individuals using alternative strategies and find that the invasion dynamics depend critically on the time scale of movement. If predation occurs early in the movement sequence, simpler strategies are likely to prevail. If predators attack later, more complex strategies invade. If there is variation in the timing of predator attacks (through variation within or between individual predators), we hypothesize that groups will consist of a mixture of strategies, dependent upon the distribution of predator attack times. Thus, behavioural diversity can evolve and be maintained in populations of animals experiencing a diverse range of predators differing solely in their attack behaviour. This has implications for our understanding of predator–prey dynamics, as the timing of predator attacks will exert selection pressure on prey behavioural responses, to which predators must respond.     

Unnatural Deaths in Shanghai from 2000 to 2009: A Retrospective Study of Forensic Autopsy Cases at the Shanghai Public Security Bureau

Shanghai is the most developed city in China and has a soaring population. This study uses forensic epidemiology to determine the relationship between unnatural deaths and the development in Shanghai, based on recently released forensic autopsy cases from the 2000s at the Shanghai Public Security Bureau (SPSB). There were 5425 accidental deaths, 2696 homicides, 429 suicides, 186 natural deaths, and 1399 deaths of undetermined cause. There was a male-to-female ratio of 2.02:1, and the average age was 40.9±18.7 years. Traffic accidents (84.2%) were the number one cause of accidental deaths, which decreased during the study period. Sharp force injury (50.6%) was the leading cause of homicides, different from Western countries, where firearms are the leading cause. Hanging (24.5%) was the leading cause of suicides, whereas drug and chemical intoxication was the leading cause in the previous decade; pesticide ingestion decreased in the 2000s. In addition to traffic accidents, manual strangulation was the leading cause of death in childhood fatalities. Children under age 2 were vulnerable to homicides. In the 2000s, there were a large number of drug overdoses, and illegal medical practices and subway-related deaths first appeared in Shanghai. A new type of terrorist attack that involved injecting people with syringes in public places was reflected in the SPSB archives. The forensic epidemiology and changes in unnatural deaths in this decade reflected their relationship with the law, policy and changes in Shanghai. Illegal medical practices, subway-related deaths and terrorist attacks were closely related to the development in Shanghai. Identifying the risks of unnatural deaths will improve public health.     

Spatiotemporal Patterns and Predictability of Cyberattacks

A relatively unexplored issue in cybersecurity science and engineering is whether there exist intrinsic patterns of cyberattacks. Conventional wisdom favors absence of such patterns due to the overwhelming complexity of the modern cyberspace. Surprisingly, through a detailed analysis of an extensive data set that records the time-dependent frequencies of attacks over a relatively wide range of consecutive IP addresses, we successfully uncover intrinsic spatiotemporal patterns underlying cyberattacks, where the term “spatio” refers to the IP address space. In particular, we focus on analyzing macroscopic properties of the attack traffic flows and identify two main patterns with distinct spatiotemporal characteristics: deterministic and stochastic. Strikingly, there are very few sets of major attackers committing almost all the attacks, since their attack “fingerprints” and target selection scheme can be unequivocally identified according to the very limited number of unique spatiotemporal characteristics, each of which only exists on a consecutive IP region and differs significantly from the others. We utilize a number of quantitative measures, including the flux-fluctuation law, the Markov state transition probability matrix, and predictability measures, to characterize the attack patterns in a comprehensive manner. A general finding is that the attack patterns possess high degrees of predictability, potentially paving the way to anticipating and, consequently, mitigating or even preventing large-scale cyberattacks using macroscopic approaches.     

Effects of Wolf Mortality on Livestock Depredations

Predator control and sport hunting are often used to reduce predator populations and livestock depredations, – but the efficacy of lethal control has rarely been tested. We assessed the effects of wolf mortality on reducing livestock depredations in Idaho, Montana and Wyoming from 1987–2012 using a 25 year time series. The number of livestock depredated, livestock populations, wolf population estimates, number of breeding pairs, and wolves killed were calculated for the wolf-occupied area of each state for each year. The data were then analyzed using a negative binomial generalized linear model to test for the expected negative relationship between the number of livestock depredated in the current year and the number of wolves controlled the previous year. We found that the number of livestock depredated was positively associated with the number of livestock and the number of breeding pairs. However, we also found that the number of livestock depredated the following year was positively, not negatively, associated with the number of wolves killed the previous year. The odds of livestock depredations increased 4% for sheep and 5–6% for cattle with increased wolf control - up until wolf mortality exceeded the mean intrinsic growth rate of wolves at 25%. Possible reasons for the increased livestock depredations at ≤25% mortality may be compensatory increased breeding pairs and numbers of wolves following increased mortality. After mortality exceeded 25%, the total number of breeding pairs, wolves, and livestock depredations declined. However, mortality rates exceeding 25% are unsustainable over the long term. Lethal control of individual depredating wolves may sometimes necessary to stop depredations in the near-term, but we recommend that non-lethal alternatives also be considered.     

Patterns of Lynx Predation at the Interface between Protected Areas and Multi-Use Landscapes in Central Europe

In Central Europe, protected areas are too small to ensure survival of populations of large carnivores. In the surrounding areas, these species are often persecuted due to competition with game hunters. Therefore, understanding how predation intensity varies spatio-temporally across areas with different levels of protection is fundamental. We investigated the predation patterns of Eurasian lynx (Lynx lynx) on roe deer (Capreolus capreolus) and red deer (Cervus elaphus) in both protected areas and multi-use landscapes of the Bohemian Forest Ecosystem. Based on 359 roe and red deer killed by 10 GPS-collared lynx, we calculated the species-specific annual kill rates and tested for effects of season and lynx age, sex and reproductive status. Because roe and red deer in the study area concentrate in unprotected lowlands during winter, we modeled spatial distribution of kills separately for summer and winter and calculated-the probability of a deer killed by lynx and-the expected number of kills for areas with different levels of protection. Significantly more roe deer (46.05–74.71/year/individual lynx) were killed than red deer (1.57–9.63/year/individual lynx), more deer were killed in winter than in summer, and lynx family groups had higher annual kill rates than adult male, single adult female and subadult female lynx. In winter the probability of a deer killed and the expected number of kills were higher outside the most protected part of the study area than inside; in summer, this probability did not differ between areas, and the expected number of kills was slightly larger inside than outside the most protected part of the study area. This indicates that the intensity of lynx predation in the unprotected part of the Bohemian Forest Ecosystem increases in winter, thus mitigation of conflicts in these areas should be included as a priority in the lynx conservation strategy.     

Intracommunity Coalitionary Killing of an Adult Male Chimpanzee at Ngogo,Kibale National Park,Uganda

Intercommunity coalitionary killing of adult and adolescent males has been documented in two chimpanzee communities in the wild, and it was strongly suspected in a third. It may increase survivorship for the attackers, their mates, and their offspring by reducing the combined strength of hostile neighbors and/or by increasing territory size and food availability, and it may help the attackers to attract mates. Lethal coalitionary attacks by males on other male members of their own communities would not provide these benefits and are not expected, given the importance of cooperation among male community members in contests for dominance rank and in both defense and offense against neighboring males. Nevertheless, intracommunity coalitionary killings associated with struggles for alpha rank occur in the wild and in captivity, and observers have seen serious gang attacks on maturing adolescent and young adult males at Mahale and Budongo: the victim in the Budongo case was killed (Fawcett and Muhumuza, 2000). I describe a lethal attack on a young adult male by a large coalition of males from his community at Ngogo, Kibale National Park, Uganda. The Ngogo community is the largest known for chimpanzees and has an unusually large number of males. The attack was not related to a struggle for alpha rank: the victim was low-ranking and the community had a well-established alpha at the time. However, the victim had risen substantially in the male hierarchy over the past few years and might have appeared threatening to many higher-ranking males. Simultaneously, he associated relatively little with most other adult males, had relatively few grooming partners and was not well integrated into the male grooming network, and had no influential allies. The combination of these social factors with the unusual demographic circumstances – which presumably meant that mating competition was relatively high and the cost of losing one male relatively low – might have triggered the attack.     

Factors Associated With the Time to Next Attack in Neuromyelitis Optica: Accelerated Failure Time Models With Random Effects

Background and Objective

Neuromyelitis optica (NMO) is an inflammatory demyelinating disorder of the central nervous system with a relapsing and remitting course. We aimed to identify factors associated with the time to next attack, including the effect of the natural disease course and the diverse treatment regimens, by applying a longitudinal statistical analysis to the individual attacks of each patient.

Methods

In total, 184 acute attacks among 58 patients with either NMO or NMO spectrum disorder with anti-aquaporin-4 antibody were assessed retrospectively. Patient demographics, clinical characteristics at each attack, and type of treatment during inter-attack periods were assessed. The dependent variable was defined as the time from each attack to the next attack (inter-attack interval). An exponential accelerated failure time model with shared gamma frailty was adapted for statistical analysis.

Results

A multivariable analysis revealed that the time from each attack to the next attack in NMO increased independently by 1.31 times (95% confidence interval (CI), 1.02–1.67; p = 0.035) with each additional cumulative attack experienced, by 5.34 times (95% CI, 1.57–18.13; p = 0.007) with combined azathioprine treatment and continued oral prednisolone, and by 4.26 times (95% CI, 1.09–16.61; p = 0.037) with rituximab treatment.

Conclusion

The time to next attack in NMO can increase naturally in the later stages of the disease as the number of cumulative attacks increases. Nevertheless, both combined azathioprine treatment with continued oral prednisolone and rituximab treatment were also associated with a longer time to next attack, independently of the natural disease course of NMO.     

Molecular mechanisms of Ebola virus pathogenesis: focus on cell death

Ebola virus (EBOV) belongs to the Filoviridae family and is responsible for a severe disease characterized by the sudden onset of fever and malaise accompanied by other non-specific signs and symptoms; in 30–50% of cases hemorrhagic symptoms are present. Multiorgan dysfunction occurs in severe forms with a mortality up to 90%. The EBOV first attacks macrophages and dendritic immune cells. The innate immune reaction is characterized by a cytokine storm, with secretion of numerous pro-inflammatory cytokines, which induces a huge number of contradictory signals and hurts the immune cells, as well as other tissues. Other highly pathogenic viruses also trigger cytokine storms, but Filoviruses are thought to be particularly lethal because they affect a wide array of tissues. In addition to the immune system, EBOV attacks the spleen and kidneys, where it kills cells that help the body to regulate its fluid and chemical balance and that make proteins that help the blood to clot. In addition, EBOV causes liver, lungs and kidneys to shut down their functions and the blood vessels to leak fluid into surrounding tissues. In this review, we analyze the molecular mechanisms at the basis of Ebola pathogenesis with a particular focus on the cell death pathways induced by the virus. We also discuss how the treatment of the infection can benefit from the recent experience of blocking/modulating cell death in human degenerative diseases.     

The Overall Situation in the South China Sea in the New Millennium: Before and After the September 11 Terrorist Attacks

This contribution reviews the overall situation in the South China Sea (SCS) between 2000 and June 2002. A number of important new developments and policy events have occurred during this period, including: the expansion of India's military presence from the Indian Ocean into the SCS; the efforts taken by Japan to promote cooperation in the SCS to deal with maritime security issues; the increase of military exercises conducted by both the claimants and nonclaimants in the SCS; the improvement of diplomatic relationships among the claimants, in particular, between China and the member states of ASEAN; the election of George W. Bush as U.S. President; the EP-3 incident and the September 11 terrorist attacks. These developments and events have the potential to affect peace and stability in the SCS. The changing security configuration of the SCS and possible responses of the claimants to the new strategic framework after the September 11 terrorist attacks, as well as their implications for managing potential conflicts in the SCS, are discussed.­     

Shoot damage by Tomicus sp. (Coleoptera: Scolytidae) and effect on Pinus yunnanensis resistance to subsequent reproductive attacks in the stem

Abstract 1 In South‐western China, Yunnan pines Pinus yunnanensis, suffer considerable damage from an undescribed Tomicus sp. previously thought to be T. piniperda. 2 To assess the effect of shoot maturation feeding (during which an aggregation process appears to occur) on host resistance to attacks on the bole, the relationships between shoot damage, bole attack density and tree survival were studied. 3 Attack distribution in the crown and in the stem did not vary between killed and surviving trees, indicating that mortality is determined by the quantity of attacks. 4 The level of shoot damage and bole attack density were positively and linearly correlated. This can be explained by the fact that bole attacks are caused by beetles coming from the crown of the same tree. 5 A critical threshold of bole attack density (around 80 attacks/m²) above which trees die was observed. However, because attacks continue after this threshold is reached, the density of failed attacks on the killed trees was used as an estimator of the threshold density. It decreased when shoot damage increased. 6 The existence of a critical threshold of shoot damage (60% damaged shoots) was also demonstrated. Above this threshold, stem attack density was always sufficiently high to kill trees. 7 The results emphasize that concentration of shoot attacks is the main reason for the extensive tree damage observed in China. 8 A model of relationships between shoot and stem attacks is proposed, suggesting that management to reduce shoot attacks would protect trees from dying by both decreasing the number of bole attacks and raising the threshold for successful attack density on the bole to levels that could not be attained.     

Dangerous animals in captivity: Ex situ tiger conflict and implications for private ownership of exotic animals

The risks associated with tiger attacks on people in the wild are well documented. There may currently be more tigers in captivity than in the wild, but relatively little is known about the risks of injury or death associated with owning and managing captive tigers and other large carnivores. The purpose of this study was to conduct a global assessment of attacks by captive tigers on people, with particular emphasis on cases in the United States. Our analysis of 30 international media sources and additional documents uncovered 59 unique incidents in 1998–2001 in which people were reportedly injured or killed by captive tigers. In the United States, seven people were reportedly killed and at least 27 were injured—a rate of 1.75 fatal attacks and at least nine nonfatal attacks per year. All but one fatal attack in the United States occurred in situations where tigers were privately owned or held in private facilities. Forty‐two percent of the victims were classified as visitors, and almost one‐quarter of the victims were under the age of 20. These results suggest that the victims underestimated the dangers posed by direct contact with these animals. In this work we review current legislation regarding captive ownership of tigers and other large exotic animals, and contradict claims by those who support private ownership of tigers and other large felids that the risks associated with owning and viewing these animals are insignificant. We conclude that the growing number of people who own tigers and other large exotic animals is cause for concern because of the danger to the animals, the handlers, and the public. The problem of private ownership of dangerous exotic animals has broad implications for tiger and large‐carnivore conservation, public health, and animal welfare. We support the regulation of private ownership of dangerous exotic animals, and encourage scientific analysis of this contentious issue. Zoo Biol 22:573–586, 2003. © 2003 Wiley‐Liss, Inc.     

Attacks on adult females with infants by non-resident males in the François langur

Infanticide by males is a common phenomenon in mammals, especially primates, as lactation lasts much longer than gestation in many species. Usually, infanticidal episodes occur soon after group takeovers, and are traditionally considered a male reproductive strategy (i.e., support the sexual selection hypothesis, Hrdy, 1974). To verify the validity of this conception, we observed one group of François’ langurs in the Nonggang Nature Reserve, China, between August 2003 and July 2004. During the study period, a François’ langur female with the youngest infant in the group was attacked three times by immigrating males, and later disappeared by the third day after the final attack. We suggest that these attacks on the female-infant dyad represent infanticide attempts by males, and may be the cause of the adult female and her infant’s disappearance. Presumably, that female dispersed with her infant to avoid infanticide and was not killed. Though these observations do not completely verify the sexual selection hypothesis, they are not inconsistent with it.