Effects of sugars on lipid bilayers during dehydration - SAXS/WAXS measurements and quantitative model

We present an X-ray scattering study of the effects of dehydration on the bilayer and chain-chain repeat spacings of dipalmitoylphosphatidylcholine bilayers in the presence of sugars. The presence of sugars has no effect on the average spacing between the phospholipid chains in either the fluid or gel phase. Using this finding, we establish that for low sugar concentrations only a small amount of sugar exclusion occurs. Under these conditions, the effects of sugars on the membrane transition temperatures can be explained quantitatively by the reduction in hydration repulsion between bilayers due to the presence of the sugars. Specific bonding of sugars to lipid headgroups is not required to explain this effect

Kinetics of the lamellar gel-fluid transition in phosphatidylcholine membranes in the presence of sugars

Phase diagrams are presented for dipalmitoylphosphatidylcholine (DPPC) in the presence of sugars (sucrose) over a wide range of relative humidities (RHs). The phase information presented here, determined by small angle X-ray scattering (SAXS), is shown to be consistent with previous results achieved by differential scanning calorimetry (DSC). Both techniques show a significant effect of sucrose concentration on the phase behaviour of this phospholipid bilayer. An experimental investigation into the effect of sugars on the kinetic behaviour of the gel to fluid transition is also presented showing that increasing the sugar content appears to slightly increase the rate at which the transition occurs

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains