Geographically isolated wetlands, those entirely surrounded by uplands, provide numerous landscap... more Geographically isolated wetlands, those entirely surrounded by uplands, provide numerous landscape-scale ecological functions, many of which are dependent on the degree to which they are hydrologically connected to nearby waters. There is a growing need for field-validated, landscape-scale approaches for classifying wetlands on the basis of their expected degree of hydrologic connectivity with stream networks. This study quantified seasonal variability in surface hydrologic connectivity (SHC) patterns between forested Delmarva bay wetland complexes and perennial/intermittent streams at 23 sites over a full-water year (2014-2015). Field data were used to develop metrics to predict SHC using hypothesized landscape drivers of connectivity duration and timing. Connection duration was most strongly related to the number and area of wetlands within wetland complexes as well as the channel width of the temporary stream connecting the wetland complex to a perennial/intermittent stream. Timi...
ABSTRACT Although recent U.S. Supreme Court rulings indicate surface hydrologic connectivity (SHC... more ABSTRACT Although recent U.S. Supreme Court rulings indicate surface hydrologic connectivity (SHC) between geographically isolated wetlands and nearby streams may be used, in part, to determine wetland jurisdictional status, and ecologic implications are considerable regardless of policies, wetland–stream SHC has rarely been quantified. Furthermore, the impact of cultivation and restoration on wetland–stream SHC is largely unknown. To help fill these knowledge gaps, we recorded SHC patterns during water year 2010 in non-perennial streams connecting Delmarva bay wetlands, which are commonly considered geographically isolated, and nearby perennial streams. We also evaluated how hydrologic wetland restoration impacts SHC relative to historical wetlands and native forested wetlands. Cumulative connection duration, number of connectivity transitions, mean connection duration, and maximum individual connection duration (D max-c ) were quantified. Forested wetlands were connected to perennial streams for a greater cumulative duration but exhibited fewer connectivity transitions relative to both historical and restored wetlands. SHC between historical and restored wetlands and nearby perennial streams did not differ with respect to any of the calculated metrics. Forested wetland-stream SHC was seasonally intermittent, exhibiting stream outflow from mid-fall to late-spring during periods of low evapotranspiration and elevated groundwater levels but lacking connectivity during summer months when evapotranspiration and groundwater were at an annual high and low, respectively. Historical and restored wetland-stream SHC was largely ephemeral, occurring in response to antecedent rainfall, particularly during winter and spring. Stepwise regression models describe cumulative connection duration and D max-c as a function of wetland, watershed, and non-perennial stream metrics including watershed relief, non-perennial stream slope, non-perennial stream length, and soil saturated hydraulic conductivity. Wetland–stream SHC has potential ecological implications, including provision of dispersal corridors for biota, biogeochemical processing of nutrients, and downstream delivery of energy, matter, and organisms, and is currently tied to wetland regulatory status in the U.S.
The Journal of Allergy and Clinical Immunology, Volume 121, Issue 2, Pages S25, February 2008, Au... more The Journal of Allergy and Clinical Immunology, Volume 121, Issue 2, Pages S25, February 2008, Authors:S. Commins; S. Lucas; J. Hosen; SM Satinover; L. Borish; TAE Platts-Mills. ...
ABSTRACT Recent reports have identified IgE antibodies to alphaGal as a cause of anaphylactic rea... more ABSTRACT Recent reports have identified IgE antibodies to alphaGal as a cause of anaphylactic reactions to the mAb cetuximab. These IgE antibodies cross-react with proteins from cat, dog, beef and pork. Previous reports showed that children in Africa had IgE ab to cat allergens despite negative skin tests and no exposure to cats. We report here the connection between IgE ab to alphaGal, cat proteins and helminth parasites.
Microbial communities are responsible for the bulk of biogeochemical processing in temporary head... more Microbial communities are responsible for the bulk of biogeochemical processing in temporary headwater streams, yet there is still relatively little known about how community structure and function respond to periodic drying. Moreover, the ability to sample temporary habitats can be a logistical challenge due to the limited capability to measure and predict the timing, intensity and frequency of wet-dry events. Unsurprisingly, published datasets on microbial community structure and function are limited in scope and temporal resolution and vary widely in the molecular methods applied. We compared environmental and microbial community datasets for permanent and temporary tributaries of two different North American headwater stream systems: Speed River (Ontario, Canada) and Parkers Creek (Maryland, USA). We explored whether taxonomic diversity and community composition were altered as a result of flow permanence and compared community composition amongst streams using different 16S microbial community methods (i.e., T-RFLP and Illumina MiSeq). Contrary to our hypotheses, and irrespective of method, community composition did not respond strongly to drying. In both systems, community composition was related to site rather than drying condition. Additional network analysis on the Parkers Creek dataset indicated a shift in the central microbial relationships between temporary and permanent streams. In the permanent stream at Parkers Creek, associations of methanotrophic taxa were most dominant, whereas associations with taxa from the order Nitrospirales were more dominant in the temporary stream, particularly during dry conditions. We compared these results with existing published studies from around the world and found a wide range in community responses to drying. We conclude by proposing three hypotheses that may address contradictory results and, when tested across systems, may expand understanding of the responses of microbial communities in temporary streams to natural and human-induced fluctuations in flow-status and permanence.
Landscape urbanization broadly alters watersheds and stream ecosystems, yet the impact of nonpoin... more Landscape urbanization broadly alters watersheds and stream ecosystems, yet the impact of nonpoint source urban inputs on the quantity, quality, and ultimate fate of dissolved organic matter (DOM) is poorly understood. We assessed DOM quality and microbial bioavailability in eight first-order Coastal Plain headwater streams along a gradient of urbanization (i.e., percent watershed impervious cover); none of the streams had point source discharges. DOM quality was measured using fluorescence excitation−emission matrices (EEMs) coupled with parallel factor analysis (PARAFAC). Bioavailability was assessed using biodegradable dissolved organic carbon (BDOC) incubations. Results showed that watershed impervious cover was significantly related to stream DOM composition: increasing impervious cover was associated with decreased amounts of natural humic-like DOM and enriched amounts of anthropogenic fulvic acid-like and protein-like DOM. Microbial bioavailability of DOM was greater in urbanized streams during spring and summer, and was related to decreasing proportions of humic-like DOM and increasing proportions of protein-like DOM. Increased bioavailability was associated with elevated extracellular enzyme activity of the initial microbial community supplied to samples during BDOC incubations. These findings indicate that changes in stream DOM quality due to watershed urbanization may impact stream ecosystem metabolism and ultimately the fate of organic carbon transported through fluvial systems.
Geographically isolated wetlands, those entirely surrounded by uplands, provide numerous landscap... more Geographically isolated wetlands, those entirely surrounded by uplands, provide numerous landscape-scale ecological functions, many of which are dependent on the degree to which they are hydrologically connected to nearby waters. There is a growing need for field-validated, landscape-scale approaches for classifying wetlands on the basis of their expected degree of hydrologic connectivity with stream networks. This study quantified seasonal variability in surface hydrologic connectivity (SHC) patterns between forested Delmarva bay wetland complexes and perennial/intermittent streams at 23 sites over a full-water year (2014-2015). Field data were used to develop metrics to predict SHC using hypothesized landscape drivers of connectivity duration and timing. Connection duration was most strongly related to the number and area of wetlands within wetland complexes as well as the channel width of the temporary stream connecting the wetland complex to a perennial/intermittent stream. Timi...
ABSTRACT Although recent U.S. Supreme Court rulings indicate surface hydrologic connectivity (SHC... more ABSTRACT Although recent U.S. Supreme Court rulings indicate surface hydrologic connectivity (SHC) between geographically isolated wetlands and nearby streams may be used, in part, to determine wetland jurisdictional status, and ecologic implications are considerable regardless of policies, wetland–stream SHC has rarely been quantified. Furthermore, the impact of cultivation and restoration on wetland–stream SHC is largely unknown. To help fill these knowledge gaps, we recorded SHC patterns during water year 2010 in non-perennial streams connecting Delmarva bay wetlands, which are commonly considered geographically isolated, and nearby perennial streams. We also evaluated how hydrologic wetland restoration impacts SHC relative to historical wetlands and native forested wetlands. Cumulative connection duration, number of connectivity transitions, mean connection duration, and maximum individual connection duration (D max-c ) were quantified. Forested wetlands were connected to perennial streams for a greater cumulative duration but exhibited fewer connectivity transitions relative to both historical and restored wetlands. SHC between historical and restored wetlands and nearby perennial streams did not differ with respect to any of the calculated metrics. Forested wetland-stream SHC was seasonally intermittent, exhibiting stream outflow from mid-fall to late-spring during periods of low evapotranspiration and elevated groundwater levels but lacking connectivity during summer months when evapotranspiration and groundwater were at an annual high and low, respectively. Historical and restored wetland-stream SHC was largely ephemeral, occurring in response to antecedent rainfall, particularly during winter and spring. Stepwise regression models describe cumulative connection duration and D max-c as a function of wetland, watershed, and non-perennial stream metrics including watershed relief, non-perennial stream slope, non-perennial stream length, and soil saturated hydraulic conductivity. Wetland–stream SHC has potential ecological implications, including provision of dispersal corridors for biota, biogeochemical processing of nutrients, and downstream delivery of energy, matter, and organisms, and is currently tied to wetland regulatory status in the U.S.
The Journal of Allergy and Clinical Immunology, Volume 121, Issue 2, Pages S25, February 2008, Au... more The Journal of Allergy and Clinical Immunology, Volume 121, Issue 2, Pages S25, February 2008, Authors:S. Commins; S. Lucas; J. Hosen; SM Satinover; L. Borish; TAE Platts-Mills. ...
ABSTRACT Recent reports have identified IgE antibodies to alphaGal as a cause of anaphylactic rea... more ABSTRACT Recent reports have identified IgE antibodies to alphaGal as a cause of anaphylactic reactions to the mAb cetuximab. These IgE antibodies cross-react with proteins from cat, dog, beef and pork. Previous reports showed that children in Africa had IgE ab to cat allergens despite negative skin tests and no exposure to cats. We report here the connection between IgE ab to alphaGal, cat proteins and helminth parasites.
Microbial communities are responsible for the bulk of biogeochemical processing in temporary head... more Microbial communities are responsible for the bulk of biogeochemical processing in temporary headwater streams, yet there is still relatively little known about how community structure and function respond to periodic drying. Moreover, the ability to sample temporary habitats can be a logistical challenge due to the limited capability to measure and predict the timing, intensity and frequency of wet-dry events. Unsurprisingly, published datasets on microbial community structure and function are limited in scope and temporal resolution and vary widely in the molecular methods applied. We compared environmental and microbial community datasets for permanent and temporary tributaries of two different North American headwater stream systems: Speed River (Ontario, Canada) and Parkers Creek (Maryland, USA). We explored whether taxonomic diversity and community composition were altered as a result of flow permanence and compared community composition amongst streams using different 16S microbial community methods (i.e., T-RFLP and Illumina MiSeq). Contrary to our hypotheses, and irrespective of method, community composition did not respond strongly to drying. In both systems, community composition was related to site rather than drying condition. Additional network analysis on the Parkers Creek dataset indicated a shift in the central microbial relationships between temporary and permanent streams. In the permanent stream at Parkers Creek, associations of methanotrophic taxa were most dominant, whereas associations with taxa from the order Nitrospirales were more dominant in the temporary stream, particularly during dry conditions. We compared these results with existing published studies from around the world and found a wide range in community responses to drying. We conclude by proposing three hypotheses that may address contradictory results and, when tested across systems, may expand understanding of the responses of microbial communities in temporary streams to natural and human-induced fluctuations in flow-status and permanence.
Landscape urbanization broadly alters watersheds and stream ecosystems, yet the impact of nonpoin... more Landscape urbanization broadly alters watersheds and stream ecosystems, yet the impact of nonpoint source urban inputs on the quantity, quality, and ultimate fate of dissolved organic matter (DOM) is poorly understood. We assessed DOM quality and microbial bioavailability in eight first-order Coastal Plain headwater streams along a gradient of urbanization (i.e., percent watershed impervious cover); none of the streams had point source discharges. DOM quality was measured using fluorescence excitation−emission matrices (EEMs) coupled with parallel factor analysis (PARAFAC). Bioavailability was assessed using biodegradable dissolved organic carbon (BDOC) incubations. Results showed that watershed impervious cover was significantly related to stream DOM composition: increasing impervious cover was associated with decreased amounts of natural humic-like DOM and enriched amounts of anthropogenic fulvic acid-like and protein-like DOM. Microbial bioavailability of DOM was greater in urbanized streams during spring and summer, and was related to decreasing proportions of humic-like DOM and increasing proportions of protein-like DOM. Increased bioavailability was associated with elevated extracellular enzyme activity of the initial microbial community supplied to samples during BDOC incubations. These findings indicate that changes in stream DOM quality due to watershed urbanization may impact stream ecosystem metabolism and ultimately the fate of organic carbon transported through fluvial systems.
Uploads
Papers by Jacob Hosen