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1.
MMWR Morb Mortal Wkly Rep ; 69(19): 599-602, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32407299

RESUMEN

The threat of introduction of coronavirus disease 2019 (COVID-19) into the United States with the potential for community transmission prompted U.S. federal officials in February 2020 to screen travelers from China, and later Iran, and collect and transmit their demographic and contact information to states for follow-up. During February 5-March 17, 2020, the California Department of Public Health (CDPH) received and transmitted contact information for 11,574 international travelers to 51 of 61 local health jurisdictions at a cost of 1,694 hours of CDPH personnel time. If resources permitted, local health jurisdictions contacted travelers, interviewed them, and oversaw 14 days of quarantine, self-monitoring, or both, based on CDC risk assessment criteria for COVID-19. Challenges encountered during follow-up included errors in the recording of contact information and variation in the availability of resources in local health jurisdictions to address the substantial workload. Among COVID-19 patients reported to CDPH, three matched persons previously reported as travelers to CDPH. Despite intensive effort, the traveler screening system did not effectively prevent introduction of COVID-19 into California. Effectiveness of COVID-19 screening and monitoring in travelers to California was limited by incomplete traveler information received by federal officials and transmitted to states, the number of travelers needing follow-up, and the potential for presymptomatic and asymptomatic transmission. More efficient methods of collecting and transmitting passenger data, including electronic provision of flight manifests by airlines to federal officials and flexible text-messaging tools, would help local health jurisdictions reach out to all at-risk travelers quickly, thereby facilitating timely testing, case identification, and contact investigations. State and local health departments should weigh the resources needed to implement incoming traveler monitoring against community mitigation activities, understanding that the priorities of each might shift during the COVID-19 pandemic.


Asunto(s)
Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Brotes de Enfermedades , Pandemias/prevención & control , Neumonía Viral/epidemiología , Neumonía Viral/prevención & control , Vigilancia en Salud Pública , California/epidemiología , Humanos , Internacionalidad , Viaje
2.
MMWR Morb Mortal Wkly Rep ; 69(19): 569-574, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32407307

RESUMEN

Identifying persons with hepatitis C virus (HCV) infection has become an urgent public health challenge because of increasing HCV-related morbidity and mortality, low rates of awareness among infected persons, and the advent of curative therapies (1). Since 2012, CDC has recommended testing of all persons born during 1945-1965 (baby boomers) for identification of chronic HCV infection (1); urban emergency departments (EDs) are well positioned venues for detecting HCV infection among these persons. The United States has witnessed an unprecedented opioid overdose epidemic since 2013 that derives primarily from commonly injected illicit opioids (e.g., heroin and fentanyl) (2). This injection drug use behavior has led to an increase in HCV infections among persons who inject drugs and heightened concern about increases in human immunodeficiency virus (HIV) and HCV infection within communities disproportionately affected by the opioid crisis (3,4). However, targeted strategies for identifying HCV infection among persons who inject drugs is challenging (5,6). During 2015-2016, EDs at the University of Alabama at Birmingham; Highland Hospital, Oakland, California; Johns Hopkins Hospital, Baltimore, Maryland; and Boston University Medical Center, Massachusetts, adopted opt-out (i.e., patients can implicitly accept or explicitly decline testing), universal hepatitis C screening for all adult patients. ED staff members offered HCV antibody (anti-HCV) screening to patients who were unaware of their status.* During similar observation periods at each site, ED staff members tested 14,252 patients and identified an overall 9.2% prevalence of positive results for anti-HCV among the adult patient population. Among the 1945-1965 birth cohort, prevalence of positive results for anti-HCV (13.9%) was significantly higher among non-Hispanic blacks (blacks) (16.0%) than among non-Hispanic whites (whites) (12.2%) (p<0.001). Among persons born after 1965, overall prevalence of positive results for anti-HCV was 6.7% and was significantly higher among whites (15.3%) than among blacks (3.2%) (p<0.001). These findings highlight age-associated differences in racial/ethnic prevalences and the potential for ED venues and opt-out, universal testing strategies to improve HCV infection awareness and surveillance for hard-to-reach populations. This opt-out, universal testing approach is supported by new recommendations for hepatitis C screening at least once in a lifetime for all adults aged ≥18 years, except in settings where the prevalence of positive results for HCV infection is <0.1% (7).


Asunto(s)
Servicio de Urgencia en Hospital , Hepatitis C/epidemiología , Hospitales Urbanos , Adulto , Anciano , Alabama/epidemiología , Baltimore/epidemiología , Boston/epidemiología , California/epidemiología , Femenino , Hepatitis C/diagnóstico , Humanos , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Prevalencia
3.
Eval Health Prof ; 43(2): 135-137, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32383409

RESUMEN

The novel 2019 Coronavirus Disease (COVID-19) pandemic has led to the closing of all but essential businesses in California. However, several nonessential businesses have remained open in Southern California despite the mandated "stay at home" order issued by the governor. As part of an ongoing vape shop project involving 88 participating shops, this study investigated the number of vape shops that remained open amidst the coronavirus outbreak and related mandates. Examination of shop social media websites and telephone calls to shops revealed that 61.4% (n = 54) have remained open, particularly within Korean/Asian and Hispanic/Latino ethnic locations (32 of the 54 shops). Importantly, walk-in service was much higher within Hispanic/Latino locations compared to African American, Korean/Asian, or non-Hispanic White neighborhoods (p = 0.03). It is not known if shops that stayed open were in direct violation of the order, didn't know all the details of the order, or found a loophole in the order and believed that they were an essential business. Better communication between the vape shop industry and public health officials during this pandemic is needed.


Asunto(s)
Comercio , Coronavirus , Características de la Residencia , Políticas de Control Social , Vapeo , Betacoronavirus , California , Comunicación , Conducta Cooperativa , Infecciones por Coronavirus/epidemiología , Sistemas Electrónicos de Liberación de Nicotina , Grupos Étnicos , Humanos , Pandemias , Neumonía Viral/epidemiología
4.
Medicine (Baltimore) ; 99(17): e19569, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32332605

RESUMEN

Hypothyroidism and chronic kidney disease (CKD) are highly prevalent conditions with a potential mechanistic link. We sought to determine whether hypothyroidism is associated with CKD among a large diverse community-based cohort.A cross-sectional study was performed (January 1, 1990-December 31, 2017) within a large integrated health system. Individuals age ≥55 years of age with outpatient measurements of thyroid stimulating hormone (TSH) and ≥2 serum creatinine values were included. Hypothyroidism was defined as TSH >4 mIU/L and/or receipt of thyroid hormone replacement and further categorized as hypothyroid status: TSH >4 mcIU/mL and attenuated-hypothyroid status: TSH <4 mcIU/mL with receipt of thyroid hormone replacement. Euthyroidism was defined as TSH <4 mIU/L and no thyroid hormone replacement. Our primary measure was CKD defined as an estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m. Multivariable logistic regression adjusting for age, sex, race, and comorbidities was used to estimate odds ratios (OR) for CKD by thyroid status.Among 378,101 individuals, 114,872 (30.4%) had hypothyroidism among whom 31,242 and 83,630 had hypothyroid and attenuated-hypothyroid statuses, respectively. Individuals with hypothyroidism had a CKD OR (95%CI) of 1.25 (1.21-1.29) compared with those with euthyroidism. Granular examination of thyroid statuses showed that hypothyroid and attenuated-hypothyroid statuses had CKD ORs (95% CI) of 1.59 (1.52-1.66) and 1.12 (1.08-1.16), respectively. A similar relationship was observed in analyses that defined CKD as an eGFR <60 L/min/1.73 m.Among individuals 55 years and older, we observed that those with hypothyroidism were more likely to have CKD. A stronger association was found among patients of hypothyroid status compared with attenuated-hypothyroid status suggesting a dose dependent relationship.


Asunto(s)
Hipotiroidismo/epidemiología , Insuficiencia Renal Crónica/epidemiología , Anciano , California/epidemiología , Comorbilidad , Estudios Transversales , Tasa de Filtración Glomerular , Humanos , Modelos Logísticos , Persona de Mediana Edad , Oportunidad Relativa , Tirotropina/sangre
5.
MMWR Morb Mortal Wkly Rep ; 69(14): 419-421, 2020 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-32271724

RESUMEN

On February 27, 2020, the Santa Clara County Public Health Department (SCCPHD) identified its first case of coronavirus disease 2019 (COVID-19) associated with probable community transmission (i.e., infection among persons without a known exposure by travel or close contact with a patient with confirmed COVID-19). At the time the investigation began, testing guidance recommended focusing on persons with clinical findings of lower respiratory illness and travel to an affected area or an epidemiologic link to a laboratory-confirmed COVID-19 case, or on persons hospitalized for severe respiratory disease and no alternative diagnosis (1). To rapidly understand the extent of COVID-19 in the community, SCCPHD, the California Department of Public Health (CDPH), and CDC began sentinel surveillance in Santa Clara County. During March 5-14, 2020, four urgent care centers in Santa Clara County participated as sentinel sites. For this investigation, county residents evaluated for respiratory symptoms (e.g., fever, cough, or shortness of breath) who had no known risk for COVID-19 were identified at participating urgent care centers. A convenience sample of specimens that tested negative for influenza virus was tested for SARS-CoV-2 RNA. Among 226 patients who met the inclusion criteria, 23% had positive test results for influenza. Among patients who had negative test results for influenza, 79 specimens were tested for SARS-CoV-2, and 11% had evidence of infection. This sentinel surveillance system helped confirm community transmission of SARS-CoV-2 in Santa Clara County. As a result of these data and an increasing number of cases with no known source of transmission, the county initiated a series of community mitigation strategies. Detection of community transmission is critical for informing response activities, including testing criteria, quarantine guidance, investigation protocols, and community mitigation measures (2). Sentinel surveillance in outpatient settings and emergency departments, implemented together with hospital-based surveillance, mortality surveillance, and serologic surveys, can provide a robust approach to monitor the epidemiology of COVID-19.


Asunto(s)
Infecciones Comunitarias Adquiridas/transmisión , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Neumonía Viral/epidemiología , Neumonía Viral/transmisión , Vigilancia de Guardia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , California/epidemiología , Niño , Preescolar , Técnicas de Laboratorio Clínico , Infecciones por Coronavirus/diagnóstico , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/diagnóstico , Adulto Joven
6.
MMWR Morb Mortal Wkly Rep ; 69(15): 472-476, 2020 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-32298249

RESUMEN

On February 26, 2020, the first U.S. case of community-acquired coronavirus disease 2019 (COVID-19) was confirmed in a patient hospitalized in Solano County, California (1). The patient was initially evaluated at hospital A on February 15; at that time, COVID-19 was not suspected, as the patient denied travel or contact with symptomatic persons. During a 4-day hospitalization, the patient was managed with standard precautions and underwent multiple aerosol-generating procedures (AGPs), including nebulizer treatments, bilevel positive airway pressure (BiPAP) ventilation, endotracheal intubation, and bronchoscopy. Several days after the patient's transfer to hospital B, a real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) test for SARS-CoV-2 returned positive. Among 121 hospital A health care personnel (HCP) who were exposed to the patient, 43 (35.5%) developed symptoms during the 14 days after exposure and were tested for SARS-CoV-2; three had positive test results and were among the first known cases of probable occupational transmission of SARS-CoV-2 to HCP in the United States. Little is known about specific risk factors for SARS-CoV-2 transmission in health care settings. To better characterize and compare exposures among HCP who did and did not develop COVID-19, standardized interviews were conducted with 37 hospital A HCP who were tested for SARS-CoV-2, including the three who had positive test results. Performing physical examinations and exposure to the patient during nebulizer treatments were more common among HCP with laboratory-confirmed COVID-19 than among those without COVID-19; HCP with COVID-19 also had exposures of longer duration to the patient. Because transmission-based precautions were not in use, no HCP wore personal protective equipment (PPE) recommended for COVID-19 patient care during contact with the index patient. Health care facilities should emphasize early recognition and isolation of patients with possible COVID-19 and use of recommended PPE to minimize unprotected, high-risk HCP exposures and protect the health care workforce.


Asunto(s)
Betacoronavirus/aislamiento & purificación , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/transmisión , Transmisión de Enfermedad Infecciosa de Paciente a Profesional , Personal de Hospital , Neumonía Viral/diagnóstico , Neumonía Viral/transmisión , Adulto , California/epidemiología , Infecciones por Coronavirus/epidemiología , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Exposición Profesional , Pandemias , Equipo de Protección Personal/estadística & datos numéricos , Personal de Hospital/estadística & datos numéricos , Neumonía Viral/epidemiología , Medición de Riesgo
7.
J Environ Manage ; 264: 110478, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32250904

RESUMEN

The current emphasis of developing countries on policies that favor the intensification of mining exploitation as the main source of incomes, has generated negative consequences for ecosystems and rural communities, mainly due to the release of highly toxic elements into the environment. This study was carried out to evaluate the effect of the Vetas-California gold mining district on As distribution in stream sediments and surface water samples from Suratá River, located in the southwestern area of Santurbán paramo, Colombia. With this aim, samples distributed along the high Suratá River basin in areas near and far from mining areas were selected. Samples were chemically characterized. The As mobility, enrichment and sources were evaluated using sequential and single extractions, enrichment factor (EF), geoaccumulation index (Igeo), and hierarchical cluster analysis (HCA). The results highlight high As content (reaching up to 484 mg/kg) in stream sediment sampled near the gold mining district. For both sediment and water, the relative As content along the Suratá River exceeded the background content by 220 and 64.9 times, respectively. From the single-stage extractions performed, the reducible fractions found in As(NaOH) and As(HCl) were higher in all cases, meaning a high level of mobility and lixiviation of the As content in water samples by changes in pH and redox potentials. The correlations estimated using Spearman coefficients show that most of the bioavailable fraction of As(Exch) is related to main sediment constituents such as S, Fe2O3, SiO2, and Al2O3 and the relative As content. Calculation of the enrichment factor (EF) confirms high enrichments around active sites of gold mining such as the municipalities of Vetas, California and Matanza with EF values of 285, 204, and 133, respectively. In addition, the Igeo values suggest moderate to strong As pollution due to the high Igeo found at the major mining effect points. The findings from this study are valuable for providing effective management options for risk prevention and control of the persistent As accumulation in Santurbán paramo.


Asunto(s)
Arsénico , Metales Pesados , Contaminantes Químicos del Agua , California , Colombia , Ecosistema , Monitoreo del Ambiente , Sedimentos Geológicos , Ríos , Dióxido de Silicio , Agua
8.
Science ; 368(6488): 230-233, 2020 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-32299932
9.
J Environ Manage ; 262: 110307, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32250790

RESUMEN

Stream and riparian zone networks embedded in agricultural landscapes provide a potential intervention point to ameliorate the negative effects of agricultural runoff by reducing transport of nitrate (NO3-) and suspended sediments (SS) downstream. However, our ability to support and promote NO3- and SS attenuation is limited by our understanding of vegetative and hydrogeomorphic controls in realistic management contexts. In addition, agricultural landscapes are heterogenous on multiple management scales, from farm field to regional water management scales, and the effect of these heterogeneities and how they interact across scales to affect vegetative and hydrogeomorphic controls is poorly explored in many settings. This is especially true in irrigated agricultural settings, where stream and riparian networks are entwined with and sensitive to water management systems. To fill these gaps, we related the vegetative and hydrogeomorphic features of 67 waterway reaches across two water management districts in the California Central Valley to reach-scale NO3- and turbidity attenuation and district-scale water quality patterns. We found that in-stream NO3- attenuation was rare, but, when it did occur, it was promoted by shallow and wide riparian banks, low flows, and high channel-edge denitrification potential. Nitrate concentrations were consistently higher in upstream reaches compared to water district outlets, suggesting that while exports from the district were low, agricultural runoff may impair within-district water resources. Turbidity attenuation was highly variable and unrelated to vegetative or hydrogeomorphic features, suggesting that onfield controls are crucial to managing suspended sediments. We conclude that waterway networks have the potential to mitigate the effects of agricultural NO3- runoff in this setting, but that more effective monitoring and adoption of NO3- attenuating features is needed. Using our findings, we make specific management and monitoring recommendations at both reach and water district scales.


Asunto(s)
Agricultura , Nitratos , California , Monitoreo del Ambiente , Óxidos de Nitrógeno , Abastecimiento de Agua
10.
Zootaxa ; 4747(3): zootaxa.4747.3.9, 2020 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-32230103

RESUMEN

A small collection of five Sponges made by E/V Nautilus on Cordell Bank National Marine Sanctuary, California, include the first report of the crinorhyzid Cladorhiza bathycrinoides Koltun off North America and a new species of Hexactinellida, Farrea. cordelli n. sp. The other three sponges in the collection are known to occur off the surrounding North-East Pacific coast, but new geographic or depth distributions are reported for these.


Asunto(s)
Poríferos , Animales , California
11.
Zootaxa ; 4751(2): zootaxa.4751.2.3, 2020 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-32230417

RESUMEN

Scanning electron (SEM) and light microscope examinations of members of Levinsenia Mesnil, 1897, species from California yielded a new species, new characters, emended name and range extension for L. kirbyorum Lovell, 2002. Specimens of L. gracilis (Tauber, 1879) from Sweden, Iceland, and California were compared and could not be distinguished on the basis of morphology. Two other Californian species, L. multibranchiata (Hartman, 1957) and L. oculata (Hartman, 1957), were also examined. SEM revealed features previously undescribed for the genus. Additional prostomial ciliary bundles, dorsal transverse ciliary branchial connections, notopodial sensory pores, and neurochaetal fascicle configurations. Levinsenia barwicki n.sp. possessing a terminal sensory organ, 4-8 leaf-like ciliate branchiae, and recurved neurochaete with distal hood is described More SEM work is necessary to confirm if these features are present among other members of Levinsenia and other Paraonidae genera. The status of Levinsenia according to the phylogenetic analysis performed by Langeneck et al. (2019, Molecular Phylogenetics and Evolution, 136, 1-13) is discussed.


Asunto(s)
Poliquetos , Animales , California , Filogenia
12.
Zootaxa ; 4728(1): zootaxa.4728.1.10, 2020 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-32230591

RESUMEN

Ortiz et al. (2018) described a new species of lysianassid amphipod, Shoemakerella fissipro, from Gulf of California, northeastern Pacific Ocean. Although the description and figures presented by Ortiz et al. (2018) fully characterize the new species, the journal issue in which the description appeared was published online only, and the article in which the new name appeared did not include a ZooBank registration number (LSID), required for validation of new names in electronic-only publications (ICZN 2012). As a result, the name Shoemakerella fissipro Ortiz, Capetillo Winfield, 2018, as published in Cahiers de Biologie Marine 59: 599-605, is not available according the International Code of Zoological Nomenclature (ICZN 1999, 2012). Therefore, the present note serves to validate name Shoemakerella fissipro by fulfilling ICZN conditions for nomenclatural availability.


Asunto(s)
Anfípodos , Animales , California , Océano Pacífico
13.
Dis Aquat Organ ; 138: 185-194, 2020 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-32213666

RESUMEN

In bivalve mollusk aquaculture, massive disease outbreaks with high mortality and large economic losses can occur, as in northwest Mexico in the 1990s. A range of pathogens can affect bivalves; one of great concern is ostreid herpesvirus 1 (OsHV-1), of which there are several strains. This virus has been detected in the Gulf of California in occasional or sporadic samplings, but to date, there have been few systematic studies. Monthly samples of Crassostrea gigas, water, and sediment were taken in the La Cruz coastal lagoon and analyzed by PCR. The native mollusk, Dosinia ponderosa, which lives outside the lagoon, was sampled as a control. The virus was found throughout the year only in C. gigas, with prevalence up to 60%. In total, 9 genotype variants were detected, and genetic analysis suggests that linear genotypic evolution has occurred from strain JF894308, present in La Cruz in 2011. There has been no evidence of the entry of new viral genotypes in the recent past, thus confinement of the virus within the lagoons of the Gulf of California could promote a native genotypic diversity in the short term.


Asunto(s)
Crassostrea , Animales , California , Virus ADN , Genotipo , México , Prevalencia
14.
Dis Aquat Organ ; 138: 207-213, 2020 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-32213668

RESUMEN

Southern sea otters Enhydra lutris nereis, a threatened marine mammal species, face numerous environmental and infectious disease challenges in their native habitat of coastal California, USA. However, there are few published cases describing neoplasia in sea otters despite their relatively long life span when cared for in aquarium settings. An 18 yr old neutered male southern sea otter, born and raised in human care, presented with an acute onset of seizures and dull mentation. Magnetic resonance imaging of the head revealed a large, central brain lesion. After no improvement with treatment, euthanasia was elected due to a poor prognosis. Grossly, a poorly demarcated, granular, tan mass expanded the cranial meninges in the longitudinal fissure at the level of the cruciate sulcus and extended into the underlying gray matter and superficial white matter. Histologically, the mass was composed of spindle cells, forming haphazardly arranged interlacing bundles and herringbone patterns, with a high mitotic count, moderate cellular pleomorphism, and prominent vascularization. Neoplastic cells demonstrated positive immunoreactivity for vimentin and negative immunoreactivity for smooth muscle actin, factor VIII-related antigen, S100, melan-A, E-cadherin, desmin, glial fibrillary acidic protein, and cytokeratin AE1/AE3. Based on gross, histologic, and immunohistochemical findings, the mass was most consistent with a primary intracranial fibrosarcoma (PIF). PIFs are a rare neoplasm in both humans and other animals with few reports in the veterinary literature. This is the first recorded case of a PIF in a sea otter.


Asunto(s)
Fibrosarcoma , Nutrias , Animales , California , Especies en Peligro de Extinción , Fibrosarcoma/veterinaria , Masculino
16.
Am J Public Health ; 110(4): 435-437, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32160000
17.
Dis Aquat Organ ; 137(3): 239-246, 2020 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-32132276

RESUMEN

Infectious disease is a major cause of mortality for sea otters Enhydra lutris, a keystone species of continued concern for conservationists. Parasitic infection has long been identified as a cause of mortality in otters in both Alaska and California, USA. Corynosoma enhydri (Acanthocephala) is the only parasite that uses sea otters as its primary definitive host and is highly prevalent in otter populations; however, it is generally considered unimportant both pathologically and ecologically, although this assumption is based on limited empirical knowledge. Research has instead focused on Profilicollis infections (P. major, P. kenti, P. altmani) as a significant source of otter mortality due to associated enteritis and peritonitis, which are threats to otter health. Here we describe acanthocephalan infections in sea otters by Profilicollis spp. and C. enhydri, from a survey comparing C. enhydri infections between northern sea otters E. lutris kenyoni (n = 12) and southern sea otters E. lutris nereis (n = 19). We report a novel infection of C. enhydri in a pup approximately 1 mo of age, which shows that the early introduction to solid food at around 3 wk by their mothers may lead to subsequent infection via infected prey items. We also document the first 2 known cases of Profilicollis infection in northern sea otters, which may present an unknown threat to the Alaskan population, or may be an interesting example of accidental infection.


Asunto(s)
Acantocéfalos , Infecciones , Nutrias , Alaska , Animales , California , Infecciones/veterinaria
18.
J Environ Manage ; 261: 110205, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32148274

RESUMEN

Winter cover crops could contribute to more sustainable agricultural production and increase resiliency to climate change; however, their adoption remains low in California. This paper seeks to understand barriers to winter cover crop adoption by monetizing their long-term economic and agronomic impacts on farm profitability in two of California's specialty crop systems: processing tomatoes and almonds. Our modeling effort provides a present, discounted valuation of the long-term use of winter cover crops through a cost-benefit analysis. A net present value model estimates the cumulative economic value of this practice. We then explore how the long-term trade-offs associated with winter cover crops can affect an operation's profits under a spectrum of hypothetical changes in California's agricultural landscape. Our analysis sheds light on the barriers to adoption by reporting benefit-cost ratios that indicate profitability across several scenarios; however, benefits and costs accrue differently over time and with long planning horizons. At the same time, a small portion of gained benefits are external to the grower. Findings from this study reveal that winter cover crops in California can be profitable in the long-term, but the extent of profit depends on the cropping system, extent of irrigation savings due to improved soil function, access to financial subsidies and climate change. Winter cover crops can return positive net benefits to growers who have flexible contractual obligations, can wait for the long-term return on investment and manage cover crops as closely as cash crops. This analysis contributes to the study of conservation agriculture practices by explaining possible reasons for low adoption through an economic valuation of the implications of soil management choices and policy counterfactuals.


Asunto(s)
Agricultura , Productos Agrícolas , California , Análisis Costo-Beneficio , Suelo
19.
J Environ Manage ; 261: 110269, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32148325

RESUMEN

The process of expanding a network of conservation areas includes identifying valuable areas for conservation, devising policies and implementing conservation actions on the ground. While the first two components are often analyzed in conservation science, the literature seldom focuses on the implementation process, particularly, how the governance structure acts as driver of conservation outcomes. In this paper, we analyze the process of development of the conservation network in California between 1910 and 2010 to test whether governance structure explains the variation in the attribution of land for conservation over time. We find that governance structure does play an important role in the development of the conservation network over the century. We find evidence that polycentric and diverse governance structures result in better conservation outcomes (i.e. more area of land acquired for conservation). Arrangements that included multiple levels of agencies (e.g. Federal, State, and County) better predict the area of conservation land per decade. Location of conservation action per county had an effect on conservation outcomes over the last decades, and we also find a strong negative effect of per capita income in the implementation of conservation actions. These results suggest that it is possible to leverage governance structure to meet future conservation challenges through the maintenance of a diverse and polycentric governance structure.


Asunto(s)
Conservación de los Recursos Naturales , California
20.
J Environ Manage ; 264: 110426, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32217315

RESUMEN

In regions experiencing aquifer depletion, planning for groundwater sustainability requires both accurate accounting of current groundwater budgets and an assessment of future conditions, with changes in recharge and pumping. Hydrologic variability, climate change effects on water flows, changing water infrastructure operations, and inherent uncertainties in modeling, challenge the plans to achieve groundwater sustainability. This paper examines the importance, magnitude, and policy implications of uncertainties in groundwater overdraft estimation for water management in California. We review water balance estimates from two regional-scale groundwater models-C2VSim and CVHM-for sub-regions within California's Central Valley, and examine the variability and uncertainty in historical and future estimates of groundwater overdraft. Assuming reductions in agricultural water use for sub-regions with overdraft, we estimate the probabilities of ending groundwater overdraft for different periods. We also obtain the economic costs associated with these reductions in agricultural production. Results from both groundwater models show significant inter-annual variability in flows affecting groundwater storage, and our model comparison highlights the uncertainty in water budget estimates for Central Valley sub-regions given the differences between models. The analysis of the probabilities of achieving sustainability at the sub-regional scale show that the average overdraft rate is important and that greater variance in annual groundwater storage increases uncertainties in ending overdraft, especially for shorter periods. Greater reductions in annual net water increases the reliability of achieving groundwater sustainability, but rising rapidly agricultural economic losses. Setting management thresholds below groundwater levels can ease meeting sustainability criteria, but also can introduce a false pathway to sustainability. Finally, we discuss policy implications for the design of local groundwater sustainability plans and state assessment and regulation of local plans.


Asunto(s)
Agua Subterránea , Abastecimiento de Agua , California , Reproducibilidad de los Resultados , Incertidumbre
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