The Effects of Social Status on Dopaminergic Regulation of Neural Circuit Activation and Behavior

Social hierarchies can be observed within communities across many species and allow for proper allocation of resources. When forming social hierarchies, animals that display the most aggressive behaviors generally emerge as dominant, while less aggressive animals are relegated to a subordinate role. The aim of this study is to address the neural bases of social regulation using zebrafish (Danio rerio) as a model organism. When paired, zebrafish form dominance hierarchies that consist of socially dominant and subordinate fish. To better understand the effects of social dominance on nervous system function we investigated the influence of social experience on the escape and swim behaviors. Using a non-invasive technique of recording field potentials, we monitored escape and swimming behavior between fish of known social status. We showed that social status affects neural activation underlying swimming and escape behaviors. Subordinates favor escape over swim, while dominants favor swim over escape. We hypothesized that a neuromodulator associated with social regulation and aggression, dopamine (DA), may influence the activation of the two underlying neural circuits responsible for these behaviors in a social status-dependent manner. To test this hypothesis, we initially looked at whether the supply of DA influenced differences in swimming and escape behavior. We augmented levels of DA through injection and observed no significant changes in the escape or swimming behavior of dominants or subordinates. Next, we determined if the interpretation of DA, via DA receptors, influenced the status-dependent behavioral differences. We manipulated the activation of DA receptors through injection of DA specific agonists and antagonists. First, antagonizing the dopamine 1 receptor (D1) decreased dominant swimming frequency and increased escape probability, while having no effect on either behavior in subordinates. Activating the D1 receptor caused no changes in escape probability or swimming frequency in either social phenotype. Second, neither application of dopamine 2 receptor (D2) agonist nor antagonist significantly altered escape probability in either social phenotype; however, blocking the D2 receptor reduced dominant swimming frequency. Finally, antagonizing the dopamine 3 receptor (D3) lowered subordinates' probability of escape with no change in swimming frequency, while showing no effect on dominant behavior. Activating the D3 receptor had no effect on dominant or subordinate escape behavior, but decreased dominant swimming. Taken together, these results suggest that the social status-dependent differences in escape and swimming behaviors of zebrafish may be influenced by dopamine receptor activation

Predicting consistent foraging ecologies of migrating waterbirds: Using stable isotope and parasite measurements as indicators of landscape use

The emergence of novel human pathogens is frequently linked with zoonotic events and human-wildlife interactions that promote disease transmission. Consequently, surveillance of wildlife populations for candidate diseases that could spread to humans is beneficial, but requires widespread collections of numerous samples. A legitimate means to acquire large sample sizes of waterfowl is through cooperation between researchers and hunters, who also work in concert with natural resource managers, landowners, and agricultural entities -e.g., aquaculture facilities. In addition to understanding the occurrence and spread of parasites and pathogens by birds, these samples can be used to answer questions about the ecology of various waterbird species. Body mass and morphometric data on hunter-donated specimen are useful for understanding bird condition and other dynamics of birds; however, when breast meat is removed prior to the acquisition of specimen weight, samples might not be as desirable. Here, we evaluate the utility of data obtained from a bird species that might be targeted by hunters and subsequently used to learn about their disease dynamics. Lesser Scaup (Aythya affinis) collected at aquaculture facilities were assessed for their stable isotope concentrations and parasites communities to learn about the birds’ foraging ecology. Discriminant analyses designed to classify birds by the aquaculture pond type from which they were collected included isotope data, Principal Components derived from parasite community data of 7 types, and birds’ body mass. We compared these to Double-crested Cormorants (Nannopterum auritum) feeding on catfish and found the two waterbird species exhibited different infracommunities of parasites Furthermore, some scaup demonstrated fish aquaculture pond type fidelity. Bird body mass was an important metric to include in analytical models when all parasite datatypes were not available. However, the combination of stable isotope concentrations and parasite infracommunity data (that includes prevalence, abundance, volume, and energy use) in models resulted in host ecology differentiation equal or better than models where bird body mass was included. Hunter-derived samples should be encouraged as a means for sample acquisition and be considered as an approach for aquaculture-wildlife conflict management as the information that can be obtained through these samples is multifaceted

Scaup Depredation on Arkansas Baitfish and Sportfish Aquaculture

Lesser scaup (Aythya affinis) and greater scaup (A. marila), hereafter scaup, consume a variety of aquatic invertebrates, plants, and occasionally small fish. Scaup have foraged on commercial aquaculture farms in the southern United States for decades. However, the types, abundance, and rate of fish exploitation by scaup on baitfish and sportfish farms are not well documented. Thus, information is needed to understand how fish and other foods influence scaup use of aquatic resources, and any potential economic effects of depredation of fish. From November–March in winters 2016–2017 and 2017–2018, we conducted 1,458 pond surveys to estimate the abundance and distribution of scaup on Arkansas baitfish and sportfish farms that commercially produce species such as golden shiners (Notemigonus crysoleucas), fathead minnows (Pimephales promelas), goldfish (Carassius auratus), and sunfish (Lepomis spp.). We also collected and processed 531 foraging scaup and quantified the proportion of scaup consuming fish and the proportion of their diet obtained from fish. Fish consumption was highly variable between years. In our survey area, we estimated total fish consumption at 1,400 kg and 60,500 kg for winters 2016–2017 and 2017–2018, respectively. Sunfish ponds experienced the maximum loss (18,000 fish/ha) during winter 2017–2018, while goldfish ponds experienced a loss of just 2,600 fish/ha during the same winter. The estimates of baitfish and sportfish loss to scaup revealed potential management strategies for minimizing fish loss and can inform economic analysis of the financial impact of scaup on producers

Foraging Ecology and Distribution of Scaup (Aythya spp.) on Arkansas Commercial Baitfish and Sportfish Farms

Lesser Scaup (Aythya affinis)and Greater Scaup (Aythya marila) have been reported to consume substantial quantities of golden shiners (Notemigonus crysoleucas), fathead minnows (Pimephales promelas), goldfish (Carassius auratus), and sunfish (Lepomis spp.) produced on Arkansas commercial baitfish and sportfish farms. The goals of this study were to investigate foraging ecology and distribution of Scaup at these facilities, and use this information to assist producers in administering bird harassment efforts more efficiently. During typical wintering period for Scaup in Arkansas (November-March), we conducted approximately 1,400 pond surveys to estimate abundance and distribution of scaup on farms in 2016-2017 and 2017-2018. Information related to pond size, fish species, fish size, and stocking density, were also obtained to enable a more detailed analysis of Scaup use. We also collected 561 Scaup from these facilities to quantify the proportion of diet obtained from fish. There was an increase in Scaup abundance and fish consumption between the first to the second winter, likely attributed to cooler temperatures during the second winter. Our distribution model predicted an increased probability of Scaup use on larger ponds containing high densities of fish, while diet analysis indicated increased fish consumption during colder winter periods. Our results can be used by farm managers to designate resources for bird harassment to particular locations and times of the winter when scaup are more likely to negatively impact the fish crop

Mastectomy patterns among older women with early invasive breast cancer in England and Wales: A population-based cohort study.

INTRODUCTION: Older women with early invasive breast cancer (EIBC) are more likely to receive a mastectomy compared with younger women. This study assessed factors associated with receiving a mastectomy among older women with EIBC, with a particular focus on comorbidity and frailty. MATERIALS AND METHODS: Women diagnosed with EIBC (stages I-IIIa) aged ≥50 years from 2014 to 2019 in English and Welsh NHS organisations who received breast surgery were identified from cancer registration datasets linked to routine hospital data. Separate multivariable logistic regression models explored factors associated with mastectomy use, within each tumour stage (T1-T3). For each tumour stage, risk-adjusted rates of mastectomy were calculated for each NHS organisation and displayed using funnel plots. RESULTS: We included 106,952 women with EIBC: 23.4% received a mastectomy as their first breast cancer surgery. Receipt of mastectomy was more common among patients with a higher tumour stage (T1: 12.3%; T2: 37.6%; T3: 77.5%), and mastectomy use increased with age within each tumour stage category (50-59 vs 80 + years: 11.8% vs 26.3% for T1; 31.5% vs 56.9% for T2; 73.4% vs 90.3% for T3). Results from a multivariable regression model showed that more severe frailty was associated with mastectomy use for women with T1 (p = 0.002) or T2 (p = 0.003) tumours, but may not be for women with T3 tumours (p = 0.041). There was no association between comorbidity and mastectomy use after accounting for frailty (all p > 0.1). Adjusting for clinical and patient factors only slightly reduced the association between age and mastectomy use. Variation in mastectomy use between NHS organisations was greatest for women with T2 EIBC (unadjusted range: 17.7% to 68.4%). DISCUSSION: Older women with EIBC are more commonly treated with mastectomy. This could not be explained by tumour characteristics or physical fitness, raising questions about whether surgical decision-making inconsistently incorporates information on patient fitness and functional age

Concordance of cancer drug therapy information derived from routinely collected hospital admissions data and the Systemic Anti-Cancer Therapy (SACT) dataset, for older women diagnosed with early invasive breast cancer in England.

BACKGROUND: Evaluating uptake of oncological treatments, and subsequent outcomes, depends on data sources containing accurate and complete information about cancer drug therapy (CDT). This study aimed to evaluate the consistency of CDT information in the Hospital Episode Statistics Admitted Patient Care (HES-APC) and Systemic Anti-Cancer Therapy (SACT) datasets for early invasive breast cancer (EIBC). METHODS: The study included women (50 + years) diagnosed with EIBC in England from 2014 to 2019 who had surgery within six months of diagnosis. Concordance of CDT recorded in HES-APC (identified using OPCS codes) and SACT was evaluated at both patient-level and cycle-level. Factors associated with CDT use captured only in HES-APC were assessed using statistical models. RESULTS: The cohort contained 129,326 women with EIBC. Overall concordance between SACT and HES-APC on CDT use was 94 %. Concordance increased over the study period (91-96 %), and there was wide variation across NHS trusts (lowest decile of trusts had concordance≤77 %; highest decile≥99 %). Among women receiving CDT, 9 % (n = 2781/31693) of use was not captured in SACT; incompleteness was worst (18 %=47/259) among women aged 80 + and those diagnosed in 2014 (21%=1121/5401). OPCS codes in HES-APC were good at identifying patient-level and cycle-level use of trastuzumab or FEC chemotherapy (fluorouracil, epirubicin, cyclophosphamide), with 89 % and 93 % concordance with SACT respectively (patient-level agreement). Among cycles of solely oral CDT recorded in SACT, only 24 % were captured in HES-APC, compared to 71 % for intravenous/subcutaneous CDT. CONCLUSIONS: Combining information in HES-APC and SACT provides a more complete picture of CDT treatment in women aged 50 + receiving surgery for EIBC than using either data source alone. HES-APC may have particular value in identifying CDT use among older women, those diagnosed less recently, and in NHS trusts with low SACT data returns