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1.
Nat Commun ; 11(1): 1351, 2020 03 12.
Article in English | MEDLINE | ID: mdl-32165619

ABSTRACT

The majority of variation in six traits critical to the growth, survival and reproduction of plant species is thought to be organised along just two dimensions, corresponding to strategies of plant size and resource acquisition. However, it is unknown whether global plant trait relationships extend to climatic extremes, and if these interspecific relationships are confounded by trait variation within species. We test whether trait relationships extend to the cold extremes of life on Earth using the largest database of tundra plant traits yet compiled. We show that tundra plants demonstrate remarkably similar resource economic traits, but not size traits, compared to global distributions, and exhibit the same two dimensions of trait variation. Three quarters of trait variation occurs among species, mirroring global estimates of interspecific trait variation. Plant trait relationships are thus generalizable to the edge of global trait-space, informing prediction of plant community change in a warming world.


Subject(s)
Plant Development , Tundra , Climate , Ecosystem , Plants/classification , Plants/genetics
2.
Glob Ecol Biogeogr ; 28(2): 78-95, 2019 Jan.
Article in English | MEDLINE | ID: mdl-31007605

ABSTRACT

AIM: Plant functional groups are widely used in community ecology and earth system modelling to describe trait variation within and across plant communities. However, this approach rests on the assumption that functional groups explain a large proportion of trait variation among species. We test whether four commonly used plant functional groups represent variation in six ecologically important plant traits. LOCATION: Tundra biome. TIME PERIOD: Data collected between 1964 and 2016. MAJOR TAXA STUDIED: 295 tundra vascular plant species. METHODS: We compiled a database of six plant traits (plant height, leaf area, specific leaf area, leaf dry matter content, leaf nitrogen, seed mass) for tundra species. We examined the variation in species-level trait expression explained by four traditional functional groups (evergreen shrubs, deciduous shrubs, graminoids, forbs), and whether variation explained was dependent upon the traits included in analysis. We further compared the explanatory power and species composition of functional groups to alternative classifications generated using post hoc clustering of species-level traits. RESULTS: Traditional functional groups explained significant differences in trait expression, particularly amongst traits associated with resource economics, which were consistent across sites and at the biome scale. However, functional groups explained 19% of overall trait variation and poorly represented differences in traits associated with plant size. Post hoc classification of species did not correspond well with traditional functional groups, and explained twice as much variation in species-level trait expression. MAIN CONCLUSIONS: Traditional functional groups only coarsely represent variation in well-measured traits within tundra plant communities, and better explain resource economic traits than size-related traits. We recommend caution when using functional group approaches to predict tundra vegetation change, or ecosystem functions relating to plant size, such as albedo or carbon storage. We argue that alternative classifications or direct use of specific plant traits could provide new insights for ecological prediction and modelling.

3.
Philos Trans R Soc Lond B Biol Sci ; 368(1624): 20120481, 2013 Aug 19.
Article in English | MEDLINE | ID: mdl-23836787

ABSTRACT

The rapidly warming temperatures in high-latitude and alpine regions have the potential to alter the phenology of Arctic and alpine plants, affecting processes ranging from food webs to ecosystem trace gas fluxes. The International Tundra Experiment (ITEX) was initiated in 1990 to evaluate the effects of expected rapid changes in temperature on tundra plant phenology, growth and community changes using experimental warming. Here, we used the ITEX control data to test the phenological responses to background temperature variation across sites spanning latitudinal and moisture gradients. The dataset overall did not show an advance in phenology; instead, temperature variability during the years sampled and an absence of warming at some sites resulted in mixed responses. Phenological transitions of high Arctic plants clearly occurred at lower heat sum thresholds than those of low Arctic and alpine plants. However, sensitivity to temperature change was similar among plants from the different climate zones. Plants of different communities and growth forms differed for some phenological responses. Heat sums associated with flowering and greening appear to have increased over time. These results point to a complex suite of changes in plant communities and ecosystem function in high latitudes and elevations as the climate warms.


Subject(s)
Climate Change , Ecosystem , Plant Development , Plants/classification , Arctic Regions , Flowers/growth & development , Internationality , Models, Biological , Plant Leaves , Seasons , Time Factors
4.
Int J Psychoanal ; 82(Pt 6): 1171-83, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11802689

ABSTRACT

This study elucidates the application of an analytic attitude to questions of gender and sexuality. The paper reports on a study group's exploration of the relative heuristic use of two important organising concepts in analytic work with female analysands: primary feminity and the phallic castration complex. A tendency to cling to one position over the other skews analytic listening. Two cases are presented of women struggling to consolidate positive feminine identifications and, to that end, working through conflicting feminine identifications and defences against a resolution of the awareness of gender differences. Analytic listening requires a view of each psychic construction as a layer to be understood in its own right yet as a cloak soon to reveal the next layer--a different construction. The study includes observations on perverse fantasies in women.


Subject(s)
Anxiety, Castration/psychology , Gender Identity , Psychoanalytic Therapy , Adult , Fantasy , Female , Freudian Theory , Humans , Psychoanalytic Interpretation
5.
J Am Psychoanal Assoc ; 44 Suppl: 511-28, 1996.
Article in English | MEDLINE | ID: mdl-9170076

ABSTRACT

Advances in the theoretical understanding of female psychology are not easily integrated into psychoanalytic practice. This paper reports on a study of female psychology and clinical practice by a group of seven female psychoanalysts. Through discussing the literature and case vignettes, we discovered a lag between current theoretical ideas and our clinical practice. The group identified an anachronistic emphasis on penis envy functioning as "bedrock." This report addresses how the group facilitated individual members' integration of theory and practice, and how this integration affected work with patients. We found that as we became open to considering a wider range of potential dynamic meanings of penis envy and female bodily concerns, we were able to explore a richer, and often surprising unfolding of vicissitudes. The discussion highlights some technical issues with this approach.


Subject(s)
Psychoanalytic Theory , Psychoanalytic Therapy , Sexuality/psychology , Women/psychology , Fantasy , Female , Freudian Theory , Gender Identity , Humans , Male , Psychosexual Development , Sex Characteristics
6.
J Nucl Med ; 33(1): 59-65, 1992 Jan.
Article in English | MEDLINE | ID: mdl-1730997

ABSTRACT

An imaging study is needed that can detect sternal wound infections and distinguish between superficial and deep sternal wound infection when a clinical diagnosis is uncertain and a decision regarding surgical intervention must be made. We retrospectively reviewed the 99mTc-leukocyte scans of 29 patients referred to rule out sternal wound infection. The presence or absence of deep or superficial sternal wound infection was determined by microbiology and long-term follow-up. Images obtained 4 and 20 hr after injection were reviewed by two nuclear physicians who were blinded to the clinical history. Findings were categorized as normal or abnormal. Abnormal images were further defined as having intense uptake at 4 and 20 hr, increasing uptake between 4 and 20 hr, or other patterns such as focal cold regions, irregular uptake at 4 and 20 hr or increasing uptake between 4 and 20 hr were 100% sensitive and 89% specific for the detection of deep sternal wound infection. The images were also useful for determining the extent of infection. Superficial sternal wound infection could not be reliably detected. The results indicate that 99mTc-leukocyte imaging is useful for the diagnosis of deep sternal wound infection.


Subject(s)
Leukocytes/diagnostic imaging , Sternum/surgery , Surgical Wound Infection/diagnostic imaging , Technetium , Adult , Aged , Humans , Middle Aged , Radionuclide Imaging , Retrospective Studies , Sternum/diagnostic imaging
7.
J Clin Microbiol ; 26(6): 1111-4, 1988 Jun.
Article in English | MEDLINE | ID: mdl-2838514

ABSTRACT

By using dram vial cell culture methods, three commercially available tests for cytomegalovirus (CMV) detection were compared: direct fluorescent monoclonal antibody staining for CMV-specific early and late antigens (direct FA), indirect fluorescent monoclonal antibody staining for a CMV-specific early antigen (indirect FA), and in situ DNA hybridization with a biotinylated CMV-specific DNA probe kit (DNA probe). Of those tests, only the indirect FA provided consistent, reliable virus detection within the initial 24 h postinfection for serial 10-fold dilutions of CMV AD169 (laboratory strain) and for three selected urine samples. However, when used prospectively, the indirect FA failed to detect virus within the initial 10 days postinfection in 15 of 78 consecutive specimens that were eventually positive by cell culture. Although the indirect FA was more sensitive than the direct FA or DNA probe, its utility appeared limited to specimens with high CMV concentrations. On the basis of these data, we recommend that indirect FA be reserved as an adjunct to standard cell culture for selected samples in diagnostic hospital laboratories.


Subject(s)
Antibodies, Monoclonal , Antigens, Viral/analysis , Cytomegalovirus/isolation & purification , DNA, Viral/analysis , Cells, Cultured , Cytomegalovirus/genetics , Cytomegalovirus/immunology , Fluorescent Antibody Technique , Humans , Nucleic Acid Hybridization
8.
Cytometry ; 9(3): 254-60, 1988 May.
Article in English | MEDLINE | ID: mdl-2837368

ABSTRACT

An early cytomegalovirus (CMV) antigen was detected with a monoclonal antibody by two-color fluorescent flow cytometry. With the aid of a human diploid fibroblast cell strain, FLOW 2000, infected with the AD169 strain of CMV, the viral antigen and the DNA content of infected or uninfected cells were measured. There was no evidence of change in the cell-cycle distribution of the infected cells. The viral antigen was detected within 30 minutes following virus adsorption at 0.1 and 1.0 plaque-forming units/cells; and the percentage of positive cells increased with time and viral dosage. All stages of the cell cycle were susceptible to viral infection and the average fluorescence was greater than the background fluorescence. Flow cytometry detected the viral antigen earlier than conventional immunofluorescent microscopy and cell culture for CMV cytopathological effect (CPE). Ten bronchoalveolar lavages assayed by flow cytometry and conventional diagnostic procedures demonstrated that flow cytometry might be useful in early diagnosis for CMV infection.


Subject(s)
Antigens, Viral/analysis , Cytomegalovirus/immunology , Flow Cytometry , Antibodies, Monoclonal , Bronchoalveolar Lavage Fluid/microbiology , Cytomegalovirus Infections/microbiology , Cytopathogenic Effect, Viral , DNA/analysis , Fibroblasts/analysis , Fibroblasts/microbiology , Fluorescent Antibody Technique , Humans , Interphase
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