Application of lidar to assess the habitat selection of an endangered small mammal in an estuarine wetland environment.

Light detection and ranging (lidar) has emerged as a valuable tool for examining the fine-scale characteristics of vegetation. However, lidar is rarely used to examine coastal wetland vegetation or the habitat selection of small mammals. Extensive anthropogenic modification has threatened the endemic species in the estuarine wetlands of the California coast, such as the endangered salt marsh harvest mouse (Reithrodontomys raviventris; SMHM). A better understanding of SMHM habitat selection could help managers better protect this species. We assessed the ability of airborne topographic lidar imagery in measuring the vegetation structure of SMHM habitats in a coastal wetland with a narrow range of vegetation heights. We also aimed to better understand the role of vegetation structure in habitat selection at different spatial scales. Habitat selection was modeled from data compiled from 15 small mammal trapping grids collected in the highly urbanized San Francisco Estuary in California, USA. Analyses were conducted at three spatial scales: microhabitat (25 m2), mesohabitat (2025 m2), and macrohabitat (~10,000 m2). A suite of structural covariates was derived from raw lidar data to examine vegetation complexity. We found that adding structural covariates to conventional habitat selection variables significantly improved our models. At the microhabitat scale in managed wetlands, SMHM preferred areas with denser and shorter vegetation and selected for proximity to levees and taller vegetation in tidal wetlands. At the mesohabitat scale, SMHM were associated with a lower percentage of bare ground and with pickleweed (Salicornia pacifica) presence. All covariates were insignificant at the macrohabitat scale. Our results suggest that SMHM preferentially selected microhabitats with access to tidal refugia and mesohabitats with consistent food sources. Our findings showed that lidar can contribute to improving our understanding of habitat selection of wildlife in coastal wetlands and help to guide future conservation of an endangered species.

PARASITES OF AN ENDANGERED HARVEST MOUSE (REITHRODONTOMYS RAVIVENTRIS HALICOETES) IN A NORTHERN CALIFORNIA MARSH.

Disease may limit recovery of endangered species. We surveyed parasites in the federally endangered salt marsh harvest mouse (SMHM; Reithrodontomys raviventris halicoetes) and sympatric rodents in Suisun Marsh (Solano County, California, USA) from April 2018 through March 2019. We investigated individual SMHM risk factors (age, sex, reproductive status, and body condition) for infection and relationships among the estimated parasite prevalence and season and habitat management (natural tidal habitats versus diked, nontidal habitats). We captured 625 individual rodents, including 439 SMHM, and tested these for infection with Bartonella spp., Borrelia spp., Rickettsia spp., Francisella tularensis, Leptospira spp., Cryptosporidium spp., Giardia spp., and Toxoplasma gondii by PCR. Over one-third (34.6%, confidence interval [CI], 30.2-39.3%) of SMHM tested positive for at least one parasite. Four percent (CI, 2.8-6.3%) of SMHM were infected with F. tularensis holarctica, a virulent bacterium that causes mortality in rodents shortly after infection. Additionally, we detected three species of Bartonella (B. henselae, B. rochalimae, B. vinsonii arupensis), Leptospira borgpetersenii serovar Ballum, Cryptosporidium sp. (deer mouse [Peromyscus maniculatus] genotype), Cryptosporidium parvum, Giardia intestinalis, and an unidentified Borrelia sp. The only parasite that was associated with habitat management was Bartonella spp., which was more prevalent in diked than tidal areas. Male SMHM were more likely to be parasitized than females, and individuals in modestly poor body condition were most likely to be infected with Bartonella spp. The estimated sample prevalence of multiple parasites varied by season and by host species. This is the first major parasite assessment in a long-endangered species, and these results will assist managers to incorporate parasitic disease into recovery planning and provide a critical baseline for future investigations, including how climatically induced habitat and species composition changes could alter disease dynamics.

A Global eDelphi Exercise to Identify Core Domains and Domain Items for the Development of a Global Registry of Alopecia Areata Disease Severity and Treatment Safety (GRASS).

Importance: A recent expert consensus exercise emphasized the importance of developing a global network of patient registries for alopecia areata to redress the paucity of comparable, real-world data regarding the effectiveness and safety of existing and emerging therapies for alopecia areata. Objective: To generate core domains and domain items for a global network of alopecia areata patient registries. Evidence Review: Sixty-six participants, representing physicians, patient organizations, scientists, the pharmaceutical industry, and pharmacoeconomic experts, participated in a 3-round eDelphi process, culminating in a face-to-face meeting at the World Congress of Dermatology, Milan, Italy, June 14, 2019. Findings: Ninety-two core data items, across 25 domains, achieved consensus agreement. Twenty further noncore items were retained to facilitate data harmonization in centers that wish to record them. Broad representation across multiple stakeholder groups was sought; however, the opinion of physicians was overrepresented. Conclusions and Relevance: This study identifies the domains and domain items required to develop a global network of alopecia areata registries. These domains will facilitate a standardized approach that will enable the recording of a comprehensive, comparable data set required to oversee the introduction of new therapies and harness real-world evidence from existing therapies at a time when the alopecia areata treatment paradigm is being radically and positively disrupted. Reuse of similar, existing frameworks in atopic dermatitis, produced by the Treatment of Atopic Eczema (TREAT) Registry Taskforce, increases the potential to reuse existing resources, creates opportunities for comparison of data across dermatology subspecialty disease areas, and supports the concept of data harmonization.

Effect of methadone on QTc in infants.

OBJECTIVE: Methadone has been associated with prolongation of the QTc interval (QTc) on electrocardiogram (ECG). In infants, the effects of methadone on the QTc are not well described. Our study's objective is to evaluate the QTc in infants being treated with methadone. METHODS: We conducted a retrospective study in infants receiving methadone. We collected demographic data, methadone dose, and QTc. A blinded-to-disease-state pediatric electrophysiologist determined the QTc. Baseline ECG was defined as an ECG obtained while not on methadone therapy, and QTc on baseline ECG was compared with treatment QTc. A significant change was defined as any absolute QTc greater than 500 or a QTc greater than 460 with an increase from baseline of greater than 40 ms. RESULTS: A total of 44 infants comprised the study population. The mean gestational age was 32.3 ± 5.51 weeks. The median age of initiation was 66 days. The median dose was 0.52 mg/kg/day in oral methadone equivalents. Nine patients were on high dose methadone (>1 mg/kg/day in oral methadone equivalents). The mean baseline QTc was 421 ± 27 and the mean change on methadone was -2 ms. No patient had a QTc greater than 500 on methadone. One patient had a QTc of 467 and 46 ms change from baseline, with no clinically significant impact. CONCLUSION: In our study population, methadone did not significantly prolong the QTc. Further prospective study is warranted to determine the utility and frequency of ECGs in infants receiving methadone.

Gestational Age-Specific Complete Blood Count Signatures in Necrotizing Enterocolitis.

Objective: Necrotizing enterocolitis (NEC) is characterized by peripheral cell abnormalities, yet few studies have analyzed the complete blood count (CBC) specifically by gestational age (GA). Our objective was to describe GA-specific immune abnormalities in NEC through a comprehensive analysis of the CBC differential. Methods: Using a cohort of 246 infants (177 cases, 69 controls) admitted to neonatal intensive care units at a single institution, we retrospectively analyzed CBCs around illness onset in NEC cases compared with controls. Cases included surgical NEC (S-NEC, 34.5%) and medical NEC (M-NEC, 65.5%). Infants were divided into those born at GA <33 and ≥33 weeks. Differences in CBC values were described as absolute and percent changes at NEC onset from baseline and at antibiotic completion after NEC. We used machine learning algorithms based on the CBC at NEC to generate predictive models for diagnosis. Results: At NEC onset, there was an acute drop in monocytes and lymphocytes along with a rise in bands in S-NEC infants born <33 weeks compared with M-NEC. In comparison, both M-NEC and S-NEC ≥33 weeks had a percent drop in neutrophils at diagnosis compared with controls. At antibiotic completion, monocytes in S-NEC <33 weeks significantly rose compared with M-NEC, yet for S-NEC ≥33 weeks, bands significantly dropped compared with M-NEC. Predictive modeling was able to accurately predict S-NEC from M-NEC and controls. Conclusion: There are discrete leukocyte patterns in NEC based on GA. The CBC at diagnosis may be useful in identifying patients who will require surgery.

Cardiopulmonary resuscitation in quaternary neonatal intensive care units: a multicenter study.

BACKGROUND: The reported incidence of cardiopulmonary resuscitation (CPR) in quaternary NICU is approximately 10-times higher than in the delivery room. However, the etiologies and outcomes of CPR in quaternary NICUs are poorly understood. We hypothesized that demographic characteristics, diagnoses, interventions, and arrest etiologies would be associated with survival to discharge after CPR. METHODS: Multicenter retrospective cohort study of four quaternary NICUs over six years (2011-2016). Demographics, resuscitation event data, and post-arrest outcomes were analyzed. The primary outcome was survival to discharge. RESULTS: Of 17,358 patients admitted to four NICUs, 200 (1.1%) experienced a CPR event, and 45.5% of those survived to discharge. Acute respiratory compromise leading to cardiopulmonary arrest occurred in 182 (91%) of the CPR events. Most neonates requiring CPR were on mechanical ventilation (79%) and had central venous access (90%) at the time of arrest. Treatments at the time of the arrest associated with decreased survival to discharge included mechanical ventilation, antibiotics, or vasopressor therapy (p < 0.01). Etiologies of arrest associated with decreased survival to discharge included multisystem organ failure, septic shock, and pneumothorax (p < 0.05). Longer duration of CPR was associated with decreased survival to discharge. The odds of surviving to discharge decreased for infants who had a primarily cardiac arrest and for infants who received epinephrine during the arrest. CONCLUSION: Approximately 1% of neonates admitted to quaternary NICUs require CPR. The most common etiology of arrest is acute respiratory compromise on a ventilator. CPR events with respiratory etiology have a favorable outcome as compared to non-respiratory causes.

Brackish Tidal Marsh Management and the Ecology of a Declining Freshwater Turtle.

Water management practices in tidal marshes of the San Francisco Bay Estuary, California are often aimed at increasing suitable habitat for threatened fish species and sport fishes. However, little is known about how best to manage habitat for other sensitive status species like the semiaquatic freshwater Western Pond Turtle (Actinemys marmorata) that is declining throughout much of its range. Here, we examined the basking activity, abundance, survival, and growth of Western Pond Turtles at two brackish water study sites in Suisun Marsh, California that differed in how they were managed, with one having passive management (i.e., no active water regulation) and another having active management (i.e., water regulated for seasonal hunting). Our results revealed that basking activity was greatest when salinity, water stage, and air temperatures were low, shortwave radiation was high, and wind levels were intermediate. These preferred habitat characteristics often reflected conditions that were naturally maintained at the passively managed, muted tidal site. We also found that turtles were more abundant and had higher survival rates in the passively managed habitat compared to the actively managed habitat (201-323 turtles/km2 and 96% survival versus 11-135 turtles/km2 and 77% survival, respectively). Finally, characteristic growth constants from von Bertalanffy models showed that turtles grew more quickly in passively managed habitat compared to the actively managed habitat. Our results suggest that management strategies for this sensitive status species may be more effective if they protect passively managed muted tidal systems that limit or delay extreme cycles of salinity and water levels and conserve elevated terrestrial buffer zones adjacent to muted and full tidal systems.

Demography of the salt marsh harvest mouse (Reithrodontomys raviventris halicoetes) and associated rodents in tidal and managed wetlands.

Suisun Marsh (Solano County, California) is the largest contiguous marsh remaining on the West Coast of the United States, and makes up approximately 10% of the wetlands remaining in the San Francisco Estuary. Suisun Marsh has been safeguarded from development through the operation of over 100 privately owned waterfowl hunting clubs, which manage for diked waterfowl habitat. However, this management-and the subsequent loss of tidal influence-has been considered harmful for some species, including the endangered salt marsh harvest mouse (SMHM; Reithrodontomys raviventris). To determine the value of tidal wetlands relative to those managed for waterfowl, we performed periodic surveys for rodents in managed and tidal wetlands over 5 years, and used capture-mark-recapture analyses to estimate demographic parameters and abundance for the three most common rodents-the northern SMHM (R. r. halicoetes), the western harvest mouse (a sympatric native species; R. megalotis, WHM), and the house mouse (a sympatric invasive species; Mus musculus). Wetland type had no effect on detection, temporary emigration, or survival for any of these species. However, fecundity and population growth for all three species were affected by an interaction of season and wetland type, although none of these parameters was consistently superior in either habitat type. Estimated abundance of SMHM and Mus was similar in both wetland types, whereas WHM were more abundant in managed wetlands. Salt marsh harvest mice also showed no affinity for any microhabitat characteristics associated with tidal wetlands. Managed wetlands in Suisun Marsh support SMHM and Mus equally, and abundances of WHM were greater than in tidal wetlands, suggesting managed wetlands may be superior in terms of supporting native rodents. As climate change and sea level rise are predicted to threaten coastal marshes, these results suggest the recovery strategy for SMHM could incorporate managed wetlands.

Physiological consequences of rising water salinity for a declining freshwater turtle.

Sea-level rise, drought and water diversion can all lead to rapid salinization of freshwater habitats, especially in coastal areas. Increased water salinities can in turn alter the geographic distribution and ecology of freshwater species including turtles. The physiological consequences of salinization for freshwater turtles, however, are poorly known. Here, we compared the osmoregulatory response of two geographically separate populations of the freshwater Western Pond Turtle (Actinemys marmorata)-a species declining across its range in western North America-to three constant salinities: 0.4 ppt, 10 ppt and 15 ppt over 2 weeks. We found that turtles from a coastal estuarine marsh population regulated their plasma osmolality at lower levels than their conspecifics from an inland freshwater creek population 45 km away. Plasma osmolalities were consistently lower in estuarine marsh turtles than the freshwater creek turtles over the entire 2-week exposure to 10 ppt and 15 ppt water. Furthermore, estuarine marsh turtles maintained plasma osmolalities within 1 SD of their mean field osmolalities over the 2-week exposure, whereas freshwater creek turtles exceeded their field values within the first few days after exposure to elevated salinities. However, individuals from both populations exhibited body mass loss in 15 ppt water, with significantly greater loss in estuarine turtles. We speculate that the greater ability to osmoregulate by the estuarine marsh turtles may be explained by their reduced feeding and drinking in elevated salinities that was not exhibited by the freshwater creek population. However, due to mass loss in both populations, physiological and behavioural responses exhibited by estuarine marsh turtles may only be effective adaptations for short-term exposures to elevated salinities, such as those from tides and when traversing saline habitats, and are unlikely to be effective for long-term exposure to elevated salinity as is expected under sea-level rise.

Infant Botulism in the Very Young Neonate: A Case Series.

Background Though botulism is a rare disease overall, all infants younger than 1 year of age are at risk of contracting infant botulism, the most prevalent form reported in the United States. Nonetheless, infant botulism is frequently omitted from the differential diagnosis of the very young neonate exclusively due to age, and the diagnosis is often only considered secondarily after a costly and prolonged work up is undertaken. Delayed diagnosis can lead not only to unnecessary testing but also to prolonged hospital stay and increased morbidity. Case This case series highlights three critically ill neonates, all younger than 30 days, who presented to our neonatal intensive care unit and were eventually diagnosed with infant botulism. The initial diagnostic dilemma is described for each of these patients and highlights the importance of early recognition of the main symptoms, in addition to consideration of important potential coinciding conditions.

Novel NLRC4 Mutation Causes a Syndrome of Perinatal Autoinflammation With Hemophagocytic Lymphohistiocytosis, Hepatosplenomegaly, Fetal Thrombotic Vasculopathy, and Congenital Anemia and Ascites.

Autoinflammatory diseases are caused by pathologic activation of the innate immune system. Primary hemophagocytic lymphohistiocytosis (HLH) is an aggressive syndrome of excessive immune activation caused by monogenic mutations resulting in cytotoxic cell defects and subsequent failure to eliminate activated macrophages. Secondary HLH is often diagnosed in cases without a known Mendelian inheritance. However, some cases of "secondary" HLH have been shown to harbor mutations with partial dysfunction of the cytotoxic system. Recently, macrophage intrinsic abnormalities caused by NLRC4 inflammasome mutations have been linked to autoinflammation and recurrent macrophage activation syndromes resembling a primary HLH. We report a case of a former 28-week preterm infant with congenital anemia, ascites, and a heavy edematous placenta with fetal thrombotic vasculopathy, who developed hepatosplenomegaly and unexplained systemic inflammation with laboratory features of HLH in the early postnatal course and died at 2 months of age. Postmortem examination confirmed the hepatosplenomegaly with marked sinusoidal hemophagocytosis, along with striking hemophagocytosis in the bone marrow and lymph nodes. There was extensive acute and chronic ischemic bowel disease with matted bowel loops, fibrous adhesions, and patchy necrotizing enterocolitis features. Whole exome sequencing analysis demonstrated a novel mosaic heterozygous NLRC4 512 C> T (p.Ser171Phe) de novo mutation predicated to cause a dominant, gain-of-function mutation resulting in a constitutively active protein. The assembly of NLRC4-containing inflammasomes via an induced self-propagation mechanism likely enables a perpetuating process of systemic macrophage activation, presumed to be initiated in utero in this patient.

IL-23 induces IL-22 and IL-17 production in response to Chlamydia muridarum genital tract infection, but the absence of these cytokines does not influence disease pathogenesis.

OBJECTIVE: Chlamydia trachomatis infections are a significant cause of reproductive tract pathology. Protective and pathological immune mediators must be differentiated to design a safe and effective vaccine. METHODS: Wild-type mice and mice deficient in IL-22 and IL-23 were infected intravaginally with Chlamydia muridarum, and their course of infection and oviduct pathology were compared. Local genital tract and draining lymph node immune responses were also examined in IL-23-deficient mice. RESULTS: IL-22- and IL-23-deficient mice exhibited normal susceptibility to infection and oviduct pathology. IL-23 was required for the development of a Chlamydia-specific Th17 response in the lymph nodes and for production of IL-22 and IL-17 in the genital tract. However, influx of Th1 and innate immune cells was not compromised in the absence of IL-23. CONCLUSION: IL-22 and IL-23 play either redundant or minimal roles in the pathogenesis of Chlamydia infection in the mouse model. Induction of Th17-associated cytokines by a Chlamydia vaccine should be avoided as these responses are not central to resolution of infection and have pathologic potential.

Novel FOXF1 mutations in sporadic and familial cases of alveolar capillary dysplasia with misaligned pulmonary veins imply a role for its DNA binding domain.

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare and lethal developmental disorder of the lung defined by a constellation of characteristic histopathological features. Nonpulmonary anomalies involving organs of gastrointestinal, cardiovascular, and genitourinary systems have been identified in approximately 80% of patients with ACD/MPV. We have collected DNA and pathological samples from more than 90 infants with ACD/MPV and their family members. Since the publication of our initial report of four point mutations and 10 deletions, we have identified an additional 38 novel nonsynonymous mutations of FOXF1 (nine nonsense, seven frameshift, one inframe deletion, 20 missense, and one no stop). This report represents an up to date list of all known FOXF1 mutations to the best of our knowledge. Majority of the cases are sporadic. We report four familial cases of which three show maternal inheritance, consistent with paternal imprinting of the gene. Twenty five mutations (60%) are located within the putative DNA-binding domain, indicating its plausible role in FOXF1 function. Five mutations map to the second exon. We identified two additional genic and eight genomic deletions upstream to FOXF1. These results corroborate and extend our previous observations and further establish involvement of FOXF1 in ACD/MPV and lung organogenesis.

The recall response induced by genital challenge with Chlamydia muridarum protects the oviduct from pathology but not from reinfection.

The significant morbidities of ectopic pregnancy and infertility observed in women after Chlamydia trachomatis genital infection result from ascension of the bacteria from the endocervix to the oviduct, where an overly aggressive inflammatory response leads to chronic scarring and Fallopian tube obstruction. A vaccine to prevent chlamydia-induced disease is urgently needed. An important question for vaccine development is whether sterilizing immunity at the level of the oviduct is essential for protection because of the possibility that a chlamydial component drives a deleterious anamnestic T cell response upon oviduct reinfection. We show that mice inoculated with attenuated plasmid-cured strains of Chlamydia muridarum are protected from oviduct pathology upon challenge with wild-type C. muridarum Nigg despite induction of a response that did not prevent reinfection of the oviduct. Interestingly, repeated abbreviated infections with Nigg also elicited recall responses that protected the oviduct from pathology despite low-level reinfection of this vulnerable tissue site. Challenged mice displayed significant decreases in tissue infiltration of inflammatory leukocytes with marked reductions in frequencies of neutrophils but significant increases in frequencies of CD4 Th1 and CD8 T cells. An anamnestic antibody response was also detected. These data indicate that exposure to a live attenuated chlamydial vaccine or repeated abbreviated genital infection with virulent chlamydiae promotes anamnestic antibody and T cell responses that protect the oviduct from pathology despite a lack of sterilizing immunity at the site.

University multi-user facility survey-2010.

Multi-user facilities serve as a resource for many universities. In 2010, a survey was conducted investigating possible changes and successful characteristics of multi-user facilities, as well as identifying problems in facilities. Over 300 surveys were e-mailed to persons identified from university websites as being involved with multi-user facilities. Complete responses were received from 36 facilities with an average of 20 years of operation. Facilities were associated with specific departments (22%), colleges (22%), and university research centers (8.3%) or were not affiliated with any department or college within the university (47%). The five most important factors to succeed as a multi-user facility were: 1) maintaining an experienced, professional staff in an open atmosphere; 2) university-level support providing partial funding; 3) broad client base; 4) instrument training programs; and 5) an effective leader and engaged strategic advisory group. The most significant problems were: 1) inadequate university financial support and commitment; 2) problems recovering full service costs from university subsidies and user fees; 3) availability of funds to repair and upgrade equipment; 4) inability to retain highly qualified staff; and 5) unqualified users dirtying/damaging equipment. Further information related to these issues and to fee structure was solicited. Overall, there appeared to be a decline in university support for facilities and more emphasis on securing income by serving clients outside of the institution and by obtaining grants from entities outside of the university.

Variation of glucosinolates in wild radish (Raphanus raphanistrum) accessions.

Glucosinolate composition was determined in wild radish accessions from eight states in the northeastern and southern United States to determine the variability of production among accessions. Glucosinolates were evaluated from roots, leaves, flowers, primary, and secondary branches. Seventeen glucosinolates were identified, with glucoerucin, glucoraphenin, glucobrassicin, and gluconasturtiin contributing 90% to 100% of the total glucosinolates. Flowers contained the highest glucosinolate concentrations, 12.07 to 55.36 µmol/g, but flowers contributed only 5.3 to 21.3% to the total glucosinolates. Of the eight accessions, the Mississippi accession produced significantly higher levels of total glucosinolates and glucosinolates which can be degraded to isothiocyanates per plant, totals of 618.97 and 563.53 µmol/plant, respectively. Total plant biomass did not differ between accessions indicating a difference in the ability of the Mississippi accession to produce glucosinolates. Further studies are needed to determine if this accession would consistently produce higher glucosinolate levels under different environmental conditions.

Glucosinolate profile variation of growth stages of wild radish (Raphanus raphanistrum).

Wild radish (Raphanus raphanistrum L.) produces glucosinolates (GSL), which are important for its use as a biofumigation or allelopathic plant for weed management. Total GSL concentrations and individual GSLs were quantified in different plant parts at different developmental stages. Eight GSLs were found in various plant tissues but glucoerucin, glucoraphenin, and glucotropaeolin comprised >90% of the total GSLs. All three are degraded to isothiocyanates, which are associated with weed suppression. Maximum GSL concentration (1942.2 micromol/plant) occurred at 50% flowering stage prior to the time of maximum biomass production, when GSL concentration was 1246.65 mumol/plant. Roots contributed <15% of the total GSL. The highest concentration of GSLs was in flowers at flowering stage, but due to the low biomass they contributed only 11.83% to the total GSL. On the basis of these results, wild radish should be incorporated into soil at 50% flowering to provide the most GSLs for weed suppression.

Beach dune sand hydrophobicity due to the presence of beach vitex ( Vitex rotundifolia L. f.).

Conservation and preservation concerns have led to efforts to understand mechanisms of invasiveness and the effects these mechanisms have on the environment. Vitex rotundifolia L. f. [beach vitex (BV)] was introduced as a salt-tolerant woody ground cover, but it has since become invasive on primary and secondary dunes in coastal areas of the southeastern United States. Much of its invasive potential may be the result of intense substrate hydrophobicity underneath established stands, which is believed to prohibit seedling establishment by other plants including native plant species. This research was conducted to better understand BV-induced sand hydrophobicity by carrying out dune surveys of BV-infested areas of the South Carolina coast, identifying the compounds responsible for this activity via chemical analysis, and quantifying hydrophobicity persistence by resampling sites following removal of above-ground BV. The findings indicated that sand under BV cover was significantly hydrophobic, that cuticular alkanes from leaves and fruits were responsible for this hydrophobicity, and that extreme substrate hydrophobicity persisted for >3 years following BV removal.

Effect of Incorporation of Brassica spp. Residues on Population Densities of Soilborne Microorganisms and on Damping-off and Fusarium Wilt of Watermelon.

Incorporating Brassica spp. residue to reduce populations of soilborne fungi and manage damping-off and Fusarium wilt of watermelon (Citrullus lanatus var. lanatus) was studied in two field experiments. Treatments included incorporating flowering Brassica napus cv. Dwarf Essex canola or B. juncea cv. Cutlass mustard and laying black polyethylene mulch at incorporation or 1 month after incorporation, methyl bromide, and a nontreated control. In both years, glucosinolates were identified and quantified in the shoots and roots of the flowering plants. In both years, the total concentration of glucosinolates incorporated per square meter was significantly higher for B. juncea than for B. napus. Isothiocyanates were inconsistently detected in the amended soils and none were detected more than 12 days postincorporation. After incorporation in 2004 and 2005, amended plots had higher populations of Fusarium oxysporum and Pythium spp. than the methyl bromide treatment, and in some treatments, populations were higher than in the control. Fluorescent Pseudomonas spp. were not suppressed in amended soils, and their populations were significantly higher in some amended treatments than those in methyl bromide-treated soils or nontreated control soils. Incidence of damping-off and severity of Fusarium wilt on seedless watermelon cv. Tri-X 313, which is susceptible to Fusarium wilt, were not consistently lower in brassica-amended soils or methyl bromide-treated plots than in nontreated control plots. Therefore, under spring conditions and methods used in this study, neither biofumigation nor methyl bromide fumigation in coastal South Carolina was an effective disease management tool for two soilborne pathogens of watermelon.