Extraction of Phospholipids from Human Erythrocyte Membranes by Hemoglobin Oxidation Products.

This investigation examines oxidation conditions under which hemoglobin extracts membrane phospholipid from erythrocytes and model membranes. In erythrocytes made echinocytic with exogenous phospholipid, addition of hemoglobin oxidized with hydrogen peroxide (H2O2) or Vitamin C (conditions that result in the formation of significant quantities of choleglobin), but not ferricyanide (which produces predominantly methemoglobin), induced dose-dependent shape reversion to less echinocytic forms, consistent with extraction of phospholipids from the exofacial side of the membrane. Erythrocytes preloaded with radiolabeled phosphatidylcholine or NBD-labeled phosphatidylcholine, phosphatidylglycerol or phosphatidic acid, exhibited greatest extraction of radiolabel or fluorescence signal with exogenous hemoglobin oxidized via H2O2 or Vitamin C, but not ferricyanide. However, with NBD-phosphatidylserine (a preferential inner monolayer intercalator), significantly less extraction of labeled lipid occurred with oxidized hemoglobin prepared under all three oxidizing conditions. In dimyristoylphosphatidylcholine liposomes containing radiolabeled phosphatidylcholine, phosphatidylserine or phosphatidylethanolamine, subsequent addition of hemoglobin oxidized with H2O2 or Vitamin C extracted radiolabeled lipid with significantly greater efficiency than ferricyanide-treated hemoglobin, with enhanced extraction detectable at levels approaching physiological plasma oxidant concentrations. Radiolabeled lipid extraction was comparable for phospholipids containing saturated acyl chains between 12 and 18 carbons but diminished significantly for oleoyl-containing phospholipids. Hemoglobin dimerization occurred at very low levels with H2O2 treatment, and even lower levels with Vitamin C treatment, and thus did not correlate to the high efficiency and consistent levels of lipid extraction observed with these treatments. These findings indicate that choleglobin extracts lipids from cell membranes regardless of headgroup or acyl chain length, through a process of direct hydrophobic interaction with the membrane surface.

Pyrolysis Reactions of 3-Oxetanone.

The pyrolysis products of gas-phase 3-oxetanone were identified via matrix-isolation Fourier transform infrared spectroscopy and photoionization mass spectrometry. Pyrolysis was conducted in a hyperthermal nozzle at temperatures from 100 to 1200 °C with the dissociation onset observed at ∼600 °C. The ring strain in the cyclic structure of 3-oxetanone causes the molecule to decompose at relatively low temperatures. Previously, only one dissociation channel, producing formaldehyde and ketene, was considered as significant in photolysis. This study presents the first experimental measurements of the thermal decomposition of 3-oxetanone demonstrating an additional dissociation channel that forms ethylene oxide and carbon monoxide. Major products include formaldehyde, ketene, carbon monoxide, ethylene oxide, ethylene, and methyl radical. The first four products stem from initial decomposition of 3-oxetanone, while the additional products, ethylene and methyl radical, are believed to be due to further reactions involving ethylene oxide.

Products from pyrolysis of gas-phase propionaldehyde.

A hyperthermal nozzle was utilized to study the thermal decomposition of propionaldehyde, CH3CH2CHO, over a temperature range of 1073-1600 K. Products were identified with two detection methods: matrix-isolation Fourier transform infrared spectroscopy and photoionization mass spectrometry. Evidence was observed for four reactions during the breakdown of propionaldehyde: α-C-C bond scission yielding CH3CH2, CO, and H, an elimination reaction forming methylketene and H2, an isomerization pathway leading to propyne via the elimination of H2O, and a ß-C-C bond scission channel forming methyl radical and (•)CH2CHO. The products identified during this experiment were CO, HCO, CH3CH2, CH3CH═C═O, H2O, CH3C≡CH, CH3, H2C═C═O, CH2CH2, CH3CH═CH2, HC≡CH, CH2CCH, H2CO, C4H2, C4H4, and CH3CHO. The first eight products result from primary or bimolecular reactions involving propionaldehyde while the remaining products occur from reactions including the initial pyrolysis products. While the pyrolysis of propionaldehyde involves reactions similar to those observed for acetaldehyde and butyraldehyde in recent studies, there are a few unique products observed which highlight the need for further study of the pyrolysis mechanism.

Intimate Partner Violence and Subsequent Depression: Examining the Roles of Neighborhood Supportive Mechanisms.

This study examines the direct effects of neighborhood supportive mechanisms (e.g., collective efficacy, social cohesion, social networks) on depressive symptoms among females as well as their moderating effects on the impact of IPV on subsequent depressive symptoms. A multilevel, multivariate Rasch model was used with data from the Project on Human Development in Chicago Neighborhoods to assess the existence of IPV and later susceptibility of depressive symptoms among 2959 adult females in 80 neighborhoods. Results indicate that neighborhood collective efficacy, social cohesion, social interactions, and the number of friends and family in the neighborhood reduce the likelihood that females experience depressive symptoms. However, living in areas with high proportions of friends and relatives exacerbates the impact of IPV on females' subsequent depressive symptoms. The findings indicate that neighborhood supportive mechanisms impact interpersonal outcomes in both direct and moderating ways, although direct effects were more pronounced for depression than moderating effects. Future research should continue to examine the positive and potentially mitigating influences of neighborhoods in order to better understand for whom and under which circumstances violent relationships and mental health are influenced by contextual factors.

Exposure to violence, substance use, and neighborhood context.

Adolescent exposure to violence and substance use are both public health problems, but how neighborhood context contributes to these outcomes is unclear. This study uses prospective data from 1416 adolescents to examine the direct and interacting influences of victimization and neighborhood factors on adolescent substance use. Based on hierarchical Bernoulli regression models that controlled for prior substance use and multiple individual-level factors, exposure to violence significantly increased the likelihood of marijuana use but not alcohol use or binge drinking. There was little evidence that community norms regarding adolescent substance use influenced rates of substance use or moderated the impact of victimization. Community disadvantage did not directly impact substance use, but the relationship between victimization and marijuana use was stronger for those in neighborhoods with greater disadvantage. The results suggest that victimization is particularly likely to affect adolescents' marijuana use, and that this relationship may be contingent upon neighborhood economic conditions.

Listeria floridensis sp. nov., Listeria aquatica sp. nov., Listeria cornellensis sp. nov., Listeria riparia sp. nov. and Listeria grandensis sp. nov., from agricultural and natural environments.

Sampling of agricultural and natural environments in two US states (Colorado and Florida) yielded 18 Listeria-like isolates that could not be assigned to previously described species using traditional methods. Using whole-genome sequencing and traditional phenotypic methods, we identified five novel species, each with a genome-wide average BLAST nucleotide identity (ANIb) of less than 85% to currently described species. Phylogenetic analysis based on 16S rRNA gene sequences and amino acid sequences of 31 conserved loci showed the existence of four well-supported clades within the genus Listeria; (i) a clade representing Listeria monocytogenes, L. marthii, L. innocua, L. welshimeri, L. seeligeri and L. ivanovii, which we refer to as Listeria sensu stricto, (ii) a clade consisting of Listeria fleischmannii and two newly described species, Listeria aquatica sp. nov. (type strain FSL S10-1188(T) = DSM 26686(T) = LMG 28120(T) = BEI NR-42633(T)) and Listeria floridensis sp. nov. (type strain FSL S10-1187(T) = DSM 26687(T) = LMG 28121(T) = BEI NR-42632(T)), (iii) a clade consisting of Listeria rocourtiae, L. weihenstephanensis and three novel species, Listeria cornellensis sp. nov. (type strain TTU A1-0210(T) = FSL F6-0969(T) = DSM 26689(T) = LMG 28123(T) = BEI NR-42630(T)), Listeria grandensis sp. nov. (type strain TTU A1-0212(T) = FSL F6-0971(T) = DSM 26688(T) = LMG 28122(T) = BEI NR-42631(T)) and Listeria riparia sp. nov. (type strain FSL S10-1204(T) = DSM 26685(T) = LMG 28119(T) = BEI NR- 42634(T)) and (iv) a clade containing Listeria grayi. Genomic and phenotypic data suggest that the novel species are non-pathogenic.

The Moderating Effects of Peer and Parental Support on the Relationship Between Vicarious Victimization and Substance Use.

General strain theory (GST) hypothesizes that youth are more likely to engage in delinquency when they experience vicarious victimization, defined as knowing about or witnessing violence perpetrated against others, but that this relationship may be attenuated for those who receive social support from significant others. Based on prospective data from youth aged 8 to 17 participating in the Project on Human Development in Chicago Neighborhoods (PHDCN), this article found mixed support for these hypotheses. Controlling for prior involvement in delinquency, as well as other risk and protective factors, adolescents who reported more vicarious victimization had an increased likelihood of alcohol use in the short term, but not the long term, and victimization was not related to tobacco or marijuana use. Peer support did not moderate the relationship between vicarious victimization and substance use, but family support did. In contrast to strain theory's predictions, the relationship between vicarious victimization and substance use was stronger for those who had higher compared with lower levels of family support. Implications of these findings for strain theory and future research are discussed.

The protective effects of neighborhood collective efficacy on adolescent substance use and violence following exposure to violence.

Research has demonstrated that exposure to violence can result in many negative consequences for youth, but the degree to which neighborhood conditions may foster resiliency among victims is not well understood. This study tests the hypothesis that neighborhood collective efficacy attenuates the relationship between adolescent exposure to violence, substance use, and violence. Data were collected from 1,661 to 1,718 adolescents participating in the Project on Human Development in Chicago Neighborhoods, who were diverse in terms of sex (51% male, 49% female), race/ethnicity (48% Hispanic, 34% African American, 14% Caucasian, and 4% other race/ethnicity), and age (mean age 12 years; range 8-16). Information on neighborhood collective efficacy was obtained from adult residents, and data from the 1990 U.S. Census were used to control for neighborhood disadvantage. Based on hierarchical modeling techniques to adjust for the clustered data, Bernoulli models indicated that more exposure to violence was associated with a greater likelihood of tobacco, alcohol, and marijuana use and perpetration of violence. Poisson models suggested that victimization was also related to a greater variety of substance use and violent behaviors. A moderating effect of collective efficacy was found in models assessing the variety of substance use; the relationship between victimization and substance use was weaker for youth in neighborhoods with higher versus lower levels of collective efficacy. These findings are consistent with literature indicating that social support can ameliorate the negative impact of victimization. This investigation extends this research to show that neighborhood social support can also help to promote resiliency among adolescents.

Thermal decomposition products of butyraldehyde.

The thermal decomposition of gas-phase butyraldehyde, CH3CH2CH2CHO, was studied in the 1300-1600 K range with a hyperthermal nozzle. Products were identified via matrix-isolation Fourier transform infrared spectroscopy and photoionization mass spectrometry in separate experiments. There are at least six major initial reactions contributing to the decomposition of butyraldehyde: a radical decomposition channel leading to propyl radical + CO + H; molecular elimination to form H2 + ethylketene; a keto-enol tautomerism followed by elimination of H2O producing 1-butyne; an intramolecular hydrogen shift and elimination producing vinyl alcohol and ethylene, a ß-C-C bond scission yielding ethyl and vinoxy radicals; and a γ-C-C bond scission yielding methyl and CH2CH2CHO radicals. The first three reactions are analogous to those observed in the thermal decomposition of acetaldehyde, but the latter three reactions are made possible by the longer alkyl chain structure of butyraldehyde. The products identified following thermal decomposition of butyraldehyde are CO, HCO, CH3CH2CH2, CH3CH2CH=C=O, H2O, CH3CH2C≡CH, CH2CH2, CH2=CHOH, CH2CHO, CH3, HC≡CH, CH2CCH, CH3C≡CH, CH3CH=CH2, H2C=C=O, CH3CH2CH3, CH2=CHCHO, C4H2, C4H4, and C4H8. The first ten products listed are direct products of the six reactions listed above. The remaining products can be attributed to further decomposition reactions or bimolecular reactions in the nozzle.

Racial/Ethnic Differences in the Relationship Between Neighborhood Disadvantage and Adolescent Substance Use.

Although social disorganization theory hypothesizes that neighborhood characteristics influence youth delinquency, the impact of neighborhood disadvantage on adolescent substance use and racial/ethnic differences in this relationship have not been widely investigated. The present study examines these issues using longitudinal data from 1,856 African American, Hispanic, and Caucasian adolescents participating in the Project on Human Development in Chicago Neighborhoods (PHDCN). The results indicated that neighborhood disadvantage did not significantly increase the likelihood of substance use for the full sample. When relationships were analyzed by race/ethnicity, one significant (p ≤ .10) effect was found; disadvantage increased alcohol use among African Americans only. The size of this effect differed significantly between African American and Hispanic youth. In no other cases did race/ethnicity moderate the impact of disadvantage on substance use. These results suggest that disadvantage is not a strong predictor of adolescent substance use, although other features of the neighborhood may affect such behaviors.

Gender differences in the effects of exposure to violence on adolescent substance use.

To date, research exploring gender differences in the relationship between exposure to community violence and substance use has been limited. This study employs longitudinal data from the Project on Human Development in Chicago Neighborhoods (PHDCN) to assess the exposure to violence-substance use relationship and explore whether this relationship varies by gender. We find that the two forms of exposure to violence-direct (primary) and indirect (secondary)-independently increase the frequency of subsequent alcohol use, binge drinking, and marijuana use among males and females. One gender difference emerged, as females who had been directly victimized engaged in more frequent binge drinking than males who had been directly victimized. Across both sexes, the effect of each form of violence weakened when other predictors of substance use were included in the models. Future directions for this research are discussed, including policy recommendations to help adolescents cope with victimization experiences.

THE CYCLE OF VIOLENCE IN CONTEXT: EXPLORING THE MODERATING ROLES OF NEIGHBORHOOD DISADVANTAGE AND CULTURAL NORMS.

Although the cycle of violence theory has received empirical support (Widom, 1989a, 1989b), in reality, not all victims of child physical abuse become involved in violence. Therefore, little is known regarding factors that may moderate the relationship between abuse and subsequent violence, particularly contextual circumstances. The current investigation used longitudinal data from 1,372 youth living in 79 neighborhoods who participated in the Project on Human Development in Chicago Neighborhoods (PHDCN), and it employed a multivariate, multilevel Rasch model to explore the degree to which neighborhood disadvantage and cultural norms attenuate or strengthen the abuse-violence relationship. The results indicate that the effect of child physical abuse on violence was weaker in more disadvantaged communities. Neighborhood cultural norms regarding tolerance for youth delinquency and fighting among family and friends did not moderate the child abuse-violence relationship, but each had a direct effect on violence, such that residence in neighborhoods more tolerant of delinquency and fighting increased the propensity for violence. These results suggest that the cycle of violence may be contextualized by neighborhood structural and cultural conditions.

Native Missing Persons Cases Will Not be Solved by Police Alone: The Case for "Missing Persons Advocates".

This study explored the potential role of victim advocacy in Native American missing person cases. Interviews with 25 tribal and non-tribal victim/social service providers were conducted to assess their perspectives on the factors which make Native Americans vulnerable to going missing, the barriers and challenges regarding reporting and investigating missing persons, as well as how victim/social service providers might better support the families of missing persons. Findings suggest that advocates perceive that responding to and offering services for Native families who experience a missing loved one will be extremely difficult because of the intersection of isolation, poverty, and jurisdictional complexities among tribal lands, combined with social service providers and law enforcement officers' lack of resources and training regarding cultural sensitivity. At the same time, advocates suggest that additional training and resources could help overcome many of these barriers and see a role for victim service providers in responding to missing and murdered Native American persons. Implications and suggestions for practice are discussed.

Farm animal contact as risk factor for transmission of bovine-associated Salmonella subtypes.

Salmonellosis is usually associated with foodborne transmission. To identify risk from animal contact, we compared animal exposures of case-patients infected with bovine-associated Salmonella subtypes with those of control-patients infected with non-bovine-associated subtypes. We used data collected in New York and Washington, USA, from March 1, 2008, through March 1, 2010. Contact with farm animals during the 5 days before illness onset was significantly associated with being a case-patient (odds ratio 3.2, p = 0.0008), after consumption of undercooked ground beef and unpasteurized milk were controlled for. Contact with cattle specifically was also significantly associated with being a case-patient (odds ratio 7.4, p = 0.0002), after food exposures were controlled for. More cases of bovine-associated salmonellosis in humans might result from direct contact with cattle, as opposed to ingestion of foods of bovine origin, than previously recognized. Efforts to control salmonellosis should include a focus on transmission routes other than foodborne.

Clinical features of human salmonellosis caused by bovine-associated subtypes in New York.

The objective of this study was to identify patient symptoms and case outcomes that were more likely to occur as a result of Salmonella infections caused by bovine-associated subtypes (isolates that matched contemporary bovine isolates from New York by serovar and pulsed-field gel electrophoresis pattern), as compared to salmonellosis caused by non-bovine-associated subtypes. Data were collected in 34 counties of New York that comprise the Foodborne Diseases Active Surveillance Network (FoodNet) catchment area of the Centers for Disease Control and Prevention Emerging Infections Program. Patients with specimen collection dates between March 1, 2008 and March 1, 2010 were included. Symptoms and outcomes of 40 cases infected with bovine-associated Salmonella subtypes were compared to those of 379 control-cases infected with Salmonella isolates that were not bovine-associated. Cases were significantly more likely to have invasive salmonellosis (odds ratio, 3.8; p-value=0.02), after adjusting for age group, gender, and race. In addition, there was a marginal association between case status and the presence of blood in the stool (p-value=0.1) while ill. These findings might have implications for patient management, as a history of consuming undercooked foods of bovine origin or having direct contact with cattle in the few days prior to illness could be useful for suggesting a more proactive diagnostic approach as well as close monitoring for the need to implement more aggressive therapy.

A whole-genome single nucleotide polymorphism-based approach to trace and identify outbreaks linked to a common Salmonella enterica subsp. enterica serovar Montevideo pulsed-field gel electrophoresis type.

In this study, we report a whole-genome single nucleotide polymorphism (SNP)-based evolutionary approach to study the epidemiology of a multistate outbreak of Salmonella enterica subsp. enterica serovar Montevideo. This outbreak included 272 cases that occurred in 44 states between July 2009 and April 2010. A case-control study linked the consumption of salami made with contaminated black and red pepper to the outbreak. We sequenced, on the SOLiD System, 47 isolates with XbaI PFGE pattern JIXX01.0011, a common pulsed-field gel electrophoresis (PFGE) pattern associated with isolates from the outbreak. These isolates represented 20 isolates collected from human sources during the period of the outbreak and 27 control isolates collected from human, food, animal, and environmental sources before the outbreak. Based on 253 high-confidence SNPs, we were able to reconstruct a tip-dated molecular clock phylogeny of the isolates and to assign four human isolates to the actual outbreak. We developed an SNP typing assay to rapidly discriminate between outbreak-related cases and non-outbreak-related cases and tested this assay on an extended panel of 112 isolates. These results suggest that only a very small percentage of the human isolates with the outbreak PFGE pattern and obtained during the outbreak period could be attributed to the actual pepper-related outbreak (20%), while the majority (80%) of the putative cases represented background cases. This study demonstrates that next-generation-based SNP typing provides the resolution and accuracy needed for outbreak investigations of food-borne pathogens that cannot be distinguished by currently used subtyping methods.

The influence of adverse childhood experiences on internalizing and externalizing problems in early adulthood: Evidence of a gene × environment × sex interaction.

BACKGROUND: Although adverse childhood experiences (ACEs) have negative effects on subsequent wellbeing, questions remain regarding how and why they do so. Sex, environmental effects, and genetic influences may play a role in both one's exposure to ACEs as well as one's reactions to ACEs. OBJECTIVE: To understand the combined genetic and environmental influences on males' and females' exposure and reactions to ACEs, and to determine whether sex differences in offending and depressive symptoms were partially impacted by genetic influences. METHODS: We employed a sample of monozygotic twins (n = 217 pairs), same-sex dizygotic twins (n = 185 pairs), and same-sex full siblings (n = 446 pairs) from the National Longitudinal Study of Adolescent to Adult Health (N = 848 pairs) and estimated a series of multivariable biometric models. Participants were aged between 12 and 21 during Wave I, between 13 and 22 at Wave II, between 18 and 26 at Wave III, and 24 and 32 at Wave IV. RESULTS: First, there appears to be a stronger genetic influence on ACEs exposure among males than females. Second, genetic influences were stronger on offending among males and depression among females. Third, ACEs moderate the genetic influences on offending and depressive symptomology among males and females: among males, genetic influences on offending decreased as exposure to ACEs increased, while among females, genetic influences on depressive symptoms decreased as exposure to ACEs increased. CONCLUSIONS: Systematic sex differences in the exposure and reactions to ACEs are at least partially due to genetic differences. Exposure to ACEs is partially influenced by genetics among males, but not females, and the more male and females' experience ACEs, the less influence genes have on their offending and depressive symptomology, respectively.

Transmission dynamics of a multidrug-resistant Salmonella typhimurium outbreak in a dairy farm.

Cattle are recognized as an important source of foodborne Salmonella causing human illness, particularly for antimicrobial-resistant strains. The transmission dynamics of multidrug-resistant (MDR) Salmonella after the onset of a clinical outbreak in a dairy farm has been rarely monitored. The early transmission of a pathogen influences the outbreak size and persistence of the pathogen at the farm level and, therefore, how long the herd represents a risk for Salmonella zoonotic transmission. The objective of this study was to describe the transmission dynamics of MDR Salmonella Typhimurium after the onset of a clinical outbreak in a dairy herd. For that purpose, fecal shedding and serological response to MDR Salmonella were monitored in a longitudinal study conducted in a dairy herd after a few cases of salmonellosis, and a stochastic transmission model was developed to predict Salmonella persistence at the pen level. The outbreak was limited to five clinical cases, and only 18 animals out of 500 cows shed Salmonella in feces. The longest shedder was culture-positive for Salmonella for at least 68 days. The isolates (n = 27) were represented by four pulsed-field gel electrophoresis patterns; three patterns were similar. With one exception, isolates were resistant to nine or more antimicrobial drugs. Simulations of the transmission model indicated that approximately 50% of the outbreaks were likely to die out within 20 days after the first animal was infected. The simulation studies indicated that salmonellosis outbreaks with few clinical cases were likely due to the extinction of the pathogen in the premises in the early phase of the outbreaks. Small population size and group structure within the farm decrease the on-farm persistence of the pathogen.

Salmonella enterica serotype Cerro among dairy cattle in New York: an emerging pathogen?

The focus of this study was Salmonella enterica serotype Cerro, a potentially emerging pathogen of cattle. Our objectives were to document the within-herd prevalence of Salmonella Cerro among a sample of New York dairy herds, to describe the antimicrobial resistance patterns and pulsed-field gel electrophoresis types of the isolates, and to elucidate the status of this serotype as a bovine pathogen. Data were collected prospectively from dairy herds throughout New York that had at least 150 lactating cows and that received clinical service from participating veterinarians. Following enrollment, Salmonella surveillance consisted of both environmental screening and disease monitoring within the herd. Herds positive by either environmental or fecal culture were sampled during three visits to estimate the within-herd prevalence of Salmonella. Among 57 enrolled herds, 44 (77%) yielded Salmonella-positive samples during the study period. Of these, 20 herds (46%) were positive for Salmonella Cerro. Upon follow-up sampling for estimation of prevalence, Cerro was identified in 10 of the 20 herds; the median within-herd Cerro prevalence was 17%, with a maximum of 53%. Antimicrobial resistance ranged from zero to nine drugs, and eight (40%) of the Cerro-positive farms generated drug-resistant isolates. Eight XbaI pulsed-field gel electrophoresis types were represented among 116 isolates tested, although 89% of these isolates shared the predominant type. Among herds with clinical cases, cattle that had signs consistent with salmonellosis were more likely to test positive for Cerro than apparently healthy cattle, as estimated by a logistic regression model that controlled for herd as a random effect (odds ratio: 3.9). There is little in the literature concerning Salmonella Cerro, and published reports suggest an absence of disease association in cattle. However, in our region there has been an apparent increase in the prevalence of this serotype among cattle with salmonellosis. Other Salmonella serotypes important to bovine health have emerged to become leading causes of human foodborne disease, and close monitoring of Cerro is warranted.

Neighborhoods and Intimate Partner Violence Against Women: The Direct and Interactive Effects of Social Ties and Collective Efficacy.

This study examines the impact of several indicators of neighborhood social ties (e.g., residents' interactions with each other; residents' ability to recognize outsiders) on intimate partner violence (IPV) against women as well as whether neighborhood collective efficacy's impact on IPV is contingent upon such ties. This study used data from 4,151 women (46% Latina, 33% African American, 17% Caucasian, on average 32 years old) in 80 neighborhoods from the Project on Human Development in Chicago Neighborhoods. We estimated a series of random effects hierarchical Bernoulli models to assess the main and interactive effects of neighborhood social ties and collective efficacy on minor and severe forms of IPV against women. Results indicate that certain neighborhood social ties are associated with higher rates of minor forms of IPV against women (but not severe forms of IPV), and collective efficacy does not appear to influence IPV against women, regardless of the level of individual or neighborhood social ties. Unlike street crime, collective efficacy does not significantly reduce IPV against women, even in neighborhoods with strong social ties that may facilitate awareness of the violence. In fact, perpetrators of minor IPV may enjoy some protective benefit in communities with social ties that make neighbors hesitant to intervene in what some might perceive as "private matters."