Differences In Psi Research Articles

A-164 Processing Speed Differences between Attention-Deficit Hyperactivity Disorder Groups with and without Co-Morbid Anxiety Diagnoses

Abstract Objective: Existing literature has identified deficits in processing speed abilities in those diagnosed with attention deficit-hyperactivity disorder (ADHD) relative to normative data (Kramer et al., 2020; Woods et al., 2002). Furthermore, research has explored the relationship between severe anxiety symptoms and processing speed in numerous populations (Petkus et al., 2005; Vissicchio et al., 2019). As such, anxiety has been demonstrated to further negatively impact processing speed in conditions in which processing speed deficits are classically observed, such as multiple sclerosis (Vissicchio et al., 2019). The current study looks to examine whether there are significant differences in PSI between a group with both ADHD and an anxiety disorder and a group with no co-morbid anxiety disorders. Method: This study uses archival data from a neuropsychology service in a private practice clinic in the Midwest. 112 adult participants were examined in this study. Processing speed was examined using the Processing Speed composite score (PSI) from the Weschler Adult Intelligence Scale-Fourth Edition (WAIS-IV). Co-morbid anxiety disorders were assessed based on the presence of a diagnosed anxiety disorder according to patient records. Results: An independent samples t-test was employed to examine differences in PSI between the group with co-morbid anxiety disorders and ADHD and the group without an anxiety disorder diagnosis. There was no significant difference in PSI between the groups (t = -1.655, p = .10). Conclusion: Overall, there was no significant difference in PSI between groups with co-morbid ADHD and anxiety and one with ADHD alone. Implications and limitations of the current study will be discussed.

Exploring Effects of Sensory Garments on Participation of Children on the Autism Spectrum: A Pretest-Posttest Repeated Measure Design.

Objective Autistic children experience sensory challenges that interfere with participation and increase parent stress. Sensory-based interventions are used to address children's behaviors affected by sensory processing difficulties, but research is limited regarding use of sensory garments to support participation of autistic children. This study explored sensory garment effects on participation, parental competence, and perceived stress of autistic children and their parents. Method Twenty-one children were recruited and 17 males with ASD and atypical sensory processing patterns completed the 14-week study. The Canadian Occupational Performance (COPM) and Goal Attainment Scaling (GAS) were used to set and monitor participation goals. After a baseline period, children wore sensory garment(s) for 8 weeks. The COPM, GAS, Parent Stress Index-Short Form (PSI-SF), and Parent Sense of Competence Scale (PSOC) were administered four times (prebaseline, before and after the intervention, and three weeks postintervention). Results There were moderate to large significant differences in both COPM and GAS scores after the intervention and from the beginning to the end of the study indicating sensory garments may improve participation of autistic children. There were no significant differences in PSI or PSOC at any timepoint. Two children rejected the garments. Conclusions Parent- or child-selected sensory garments may improve participation in individually meaningful activities for children who can tolerate wearing them. Children's improvement in participation did not improve parent stress or competence, possibly due to the passive nature of the intervention. More research is needed explore the influence of heterogeneous sensory patterns on response to intervention.

Physiological responses of Norway spruce (Picea abies) seedlings to drought stress

Four-year-old seedlings of Picea abies [L.] Karst (Norway spruce) were grown in semi-controlled conditions with three watering regimes. The seedlings in the control group (c) were watered to prevent any dehydration effect. The two remaining groups were subjected to mild (ms) and severe water stress (ss), respectively. The following physiological variables were monitored until ss seedlings began to die: leaf water potential (psi(L)), stomatal conductance (g(s)), CO(2) exchange (P(N)), free proline content (Pro), total chlorophyll (a + b) concentration (Chl(t)) and the maximal photochemical efficiency of photosystem II (F(v)/F(m)). The results indicate that not all observed physiological parameters display the same degree of sensitivity to dehydration. After Day 12 of dehydration, psi(L) of ss seedlings was already significantly lower than that of the two other groups. On Day 26, significant differences in psi(L) were recorded among all treatments. Decreasing values of water potential were accompanied by early changes in P(N), g(s) and Pro. A significant decrease in Chl(t) and F(v)/F(m) were only observed during the more advanced stages of dehydration. These results demonstrate that the drought response of P. abies seedlings include a number of parallel physiological and biochemical changes in concert, enhancing the capability of plants to survive and grow during drought periods, but only to a point.

Soil water availability and rooting depth as determinants of hydraulic architecture of Patagonian woody species

Adaptations of species to capture limiting resources is central for understanding structure and function of ecosystems. We studied the water economy of nine woody species differing in rooting depth in a Patagonian shrub steppe from southern Argentina to understand how soil water availability and rooting depth determine their hydraulic architecture. Soil water content and potentials, leaf water potentials (Psi(Leaf)), hydraulic conductivity, wood density (rho(w)), rooting depth, and specific leaf area (SLA) were measured during two summers. Water potentials in the upper soil layers during a summer drought ranged from -2.3 to -3.6 MPa, increasing to -0.05 MPa below 150 cm. Predawn Psi(Leaf) was used as a surrogate of weighted mean soil water potential because no statistical differences in Psi(Leaf) were observed between exposed and covered leaves. Species-specific differences in predawn Psi(Leaf) were consistent with rooting depths. Predawn Psi(Leaf) ranged from -4.0 MPa for shallow rooted shrubs to -1.0 MPa for deep-rooted shrubs, suggesting that the roots of the latter have access to abundant moisture, whereas shallow-rooted shrubs are adapted to use water deposited mainly by small rainfall events. Wood density was a good predictor of hydraulic conductivity and SLA. Overall, we found that shallow rooted species had efficient water transport in terms of high specific and leaf specific hydraulic conductivity, low rho(w), high SLA and a low minimum Psi(Leaf) that exhibited strong seasonal changes, whereas deeply rooted shrubs maintained similar minimum Psi(Leaf) throughout the year, had stems with high rho(w) and low hydraulic conductivity and leaves with low SLA. These two hydraulic syndromes were the extremes of a continuum with several species occupying different portions of a gradient in hydraulic characteristics. It appears that the marginal cost of having an extensive root system (e.g., high rho(w) and root hydraulic resistance) contributes to low growth rates of the deeply rooted species.

Impact of deficit irrigation on water use efficiency and carbon isotope composition (δ13C) of field-grown grapevines under Mediterranean climate

The objective of this study was to evaluate the effect of deficit irrigation on intrinsic water use efficiency (A/g(s)) and carbon isotope composition (delta13C) of two grapevine cultivars (Moscatel and Castelão), growing in a commercial vineyard in SW Portugal. The study was done in two consecutive years (2001 and 2002). The treatments were full irrigation (FI), corresponding to 100% of crop evapotranspiration (ETc), rain-fed (no irrigation, NI), and two types of deficit irrigation (50% ETc): (i) by supplying the water either to one side of the root system or to the other, which is partial rootzone drying (PRD), or (ii) dividing the same amount of water by the two sides of the root system, the normal deficit irrigation (DI). The water supplied to the PRD treatment alternated sides approximately every 15 d. The values of predawn leaf water potential (Psi(pd)) and the cumulative integral of Psi(pd) (S(Psi)) during the season were lower in 2001 than in the 2002 growing season. Whereas differences in Psi(pd) and S(Psi) between PRD and DI were not significantly different in 2001, in 2002 (a dryer year) both cultivars showed lower values of S(Psi) in the PRD treatment as compared with the DI treatment. This suggests that partial rootzone drying may have a positive effect on water use under dryer conditions, either as a result of better stomatal control and/or reduced vigour. The effects of the water treatments on delta13C were more pronounced in whole grape berries and pulp than in leaves. The delta13C of pulp showed the best correlation with intrinsic water use efficiency (A/g(s)) as well as with S(Psi). In spite of the better water status observed in PRD compared with DI in the two cultivars in 2002, no statistical differences between the two treatments were observed in A/g(s) and delta13C. On the other hand, they showed a higher delta13C compared with FI. In conclusion, it is apparent that the response to deficit irrigation varies with the environmental conditions of the particular year, the driest conditions exacerbating the differences among treatments. The highest values of delta13C found in the pulp of NI vines in Castelão compared with Moscatel suggest different sensitivities to water deficits in the two cultivars, as was empirically observed.

Variation in water relations characteristics of terminal shoots of Port-Orford-cedar (Chamaecyparis lawsoniana) seedlings.

We measured water relations attributes of the terminal shoots of 3-year-old Port-Orford-cedar (Chamaecyparis lawsoniana (A. Murr.) Parl.) seedlings that represented its geographic range. Pressure-volume curves were developed and osmotic potentials at full (psi(sf)) and zero turgor (psi(sz)), relative water content at zero turgor, and an index of tissue elasticity (IE) were calculated for 38 families during early, mid- and late summer at an inland nursery, and for 12 of these families during mid- and late summer at a coastal nursery. Compared with other conifer species, psi(sz) was high (-1.4 to -1.5 MPa) and declined in seedlings at both nurseries as the season progressed. Both IE and osmotic amplitude (psi(sf)-psi(sz)) increased during the season. Osmotic potential at zero turgor was lower and osmotic amplitude greater in seedlings at the inland nursery than at the coastal nursery. Correlations of water relations attributes with geographic location of the seed sources were weak and usually not significant. High elevation southern sources exhibited smaller differences in psi(sz) between nurseries than low elevation northern sources. The small differences in water relations attributes among sources and between nurseries suggest that some may be of marginal physiological importance; however, sources that produced larger seedlings appeared to be less desiccation tolerant. We conclude that, when moving genotypes during reforestation, decisions based on patterns in tree size and timing of growth will account for these small differences in water relations.

Shoot water relations of mature black spruce families displaying a genotype x environment interaction in growth rate. II. Temporal trends and response to varying soil water conditions.

Pressure-volume curves and shoot water potentials were determined for black spruce (Picea mariana (Mill.) BSP) trees from four full-sib families at the Petawawa Research Forest, Ontario, Canada. Trees were sampled from a dry site in 1992 and from the dry site and a wet site in 1993. Modulus of elasticity (epsilon), osmotic potential at turgor loss point (Psi(tlp)) and relative water at turgor loss point (RWC(tlp)) all decreased during the growing season. Osmotic potential at saturation (Psi(sat)) and turgor displayed no general temporal trend. Across a range of environmental conditions, Female 59 progeny had equal or lower Psi(sat), and higher or similar epsilon, mean turgor pressure (P(x)) and predawn turgor pressure (P(pd)) compared with Female 63 progeny. Osmotic potential at saturation decreased as water stress increased from mild to moderate and increased as water stress increased from moderate to severe. Stable genetic differences in Psi(sat) were maintained by the same rate of osmotic adjustment from low to moderate water stress. Modulus of elasticity and RWC(tlp) decreased with decreasing water availability, whereas Psi(tlp) showed no response. The combined effects of Psi(sat) and epsilon resulted in no change in P(pd) as water stress increased from low to moderate values, but turgor declined sharply as water stress increased from moderate to high values. We conclude that drought tolerance traits strongly influence the growth of these black spruce families across sites of varying water availability.

Shoot water relations of mature black spruce families displaying a genotype x environment interaction in growth rate. I. Family and site effects over three growing seasons.

Pressure-volume curves were determined for black spruce (Picea mariana (Mill.) BSP) trees from four full-sib families. During the first two years, trees were measured from a plantation on a dry site. In the third year, trees were sampled from the dry site and a wet site. Diurnal measurements of shoot water potential allowed in situ shoot turgor to be estimated in addition to standard water relations traits. Over all years, Female 59 progeny displayed lower osmotic potentials at saturation (Psi(sat)) than Female 63 progeny. Genetic differences in Psi(sat) were similar on both the dry and wet sites. Modulus of elasticity (epsilon) was greater for Female 59 progeny than for Female 63 progeny, producing a compensatory effect resulting in no genetic or site differences in osmotic potential at turgor loss point (Psi(tlp)) or relative water content at turgor loss point (RWC(tlp)). Mean and predawn shoot turgor pressures (P(x) and P(pd)) were higher for Female 59 progeny than for Female 63 progeny and higher at the wet site than the dry site. Genotype x environment trends were observed; compared to Female 63 progeny, Female 59 progeny displayed 9.8 and 5.1% higher P(pd) on the dry and wet sites, respectively, and 3.4 and 9.8% greater P(pd) values in wet and dry years, respectively. Tree volume growth showed no relationship to Psi(tlp) or RWC(tlp), but was correlated with Psi(sat) and P(x); however, the strongest correlation was with P(pd) (r = 0.90).

Water relations of several hardwood species in response to throughfall manipulation in an upland oak forest during a wet year.

We investigated the effects of altered precipitation on leaf osmotic potential at full turgor (Psi(pio)) of several species in an upland oak forest during the 1994 growing season as part of a Throughfall Displacement Experiment at the Walker Branch Watershed near Oak Ridge, Tennessee. The main species sampled included overstory chestnut oak (Quercus prinus L.), white oak (Q. alba L.), red maple (Acer rubrum L.); intermediates sugar maple (A. saccharum L.) and blackgum (Nyssa sylvatica Marsh.); and understory dogwood (Cornus florida L.) and red maple. The precipitation treatments were: ambient precipitation; ambient minus 33% of throughfall (dry); and ambient plus 33% of throughfall (wet). Except in late September, midday leaf water potentials (Psi(l)) were generally high in all species in all treatments, ranging from -0.31 to -1.34 MPa for C. florida, -0.58 to -1.51 MPa for A. rubrum, and -0.78 to -1.86 MPa for Q. prinus. Both treatment and species differences in Psi(pio) were evident, with oak species generally exhibiting lower Psi(pio) than A. saccharum, A. rubrum, C. florida, and N. sylvatica. The Psi(pio) of C. florida saplings declined in the dry treatment, and Q. prinus, Q. alba, and A. saccharum all exhibited a declining trend of Psi(pio) in the dry treatment, although Psi(pio) of Q. prinus leaves increased in late August, corresponding to a recovery in soil water potential. Cornus florida exhibited osmotic adjustment with the largest adjustment coinciding with the period of lowest soil water potential in June. The only other species to exhibit osmotic adjustment was Q. prinus, which also maintained a lower baseline Psi(pio) than the other species. We conclude that a 33% reduction of throughfall is sufficient both to alter the water relations of some species in the upland oak forest and to enable the identification of those species capable of osmotic adjustment to a short-term drought during a wet year.

Drought tolerance, growth partitioning and vigor in eucalypt seedlings and rooted cuttings.

To clarify the physiological basis of productivity differences among rooted cuttings and seedlings of eucalypt species, relationships between morphology and water relations were examined in 4-month-old seedlings of Eucalyptus grandis W. Hill ex Maiden, E. urophylla S.T. Blake and E. cloeziana F. Muell. and in 4-month-old rooted cuttings of three E. grandis cultivars. Four-month-old seedlings had greater dry weights, lower leaf area/root dry weight (LA/RDW) ratios and lower shoot/root dry weight (S/R) ratios than 4-month-old rooted cuttings. For all cultivars of E. grandis, tall rooted cuttings, as defined by height at age 4 weeks, had greater dry weights by age 4 months and lower LA/RDW and S/R ratios than short rooted cuttings. There were differences in height growth, dry matter productivity and relative shoot and root development among cuttings of different E. grandis cultivars, but these differences were not as great as the differences between short and tall grades of the same cultivar and between seedlings and cuttings. Consistent with the differences in LA/RDW and S/R ratios, seedlings had higher daytime water potentials (Psi(x)) than cuttings, and tall cuttings had higher daytime values of Psi(x) than short cuttings. Differences in Psi(x) were also related to stomatal conductance (g(wv)), which was up to 300% greater in short cuttings than in tall cuttings. Among seedlings, those of E. cloeziana, which had the smallest dry weight at age 4 months, had the highest g(wv), whereas those of E. grandis, which had the greatest dry weight at age 4 months, had the lowest g(wv). Unlike seedlings and the tall cuttings, short cuttings lost turgor when subjected to drought. The differences observed in susceptibility to water stress may account in part for the associated differences in dry matter production. Xylem pressure potential and relative water deficit at zero turgor did not differ significantly among the types of plants studied, which suggests that differences in growth rates were not the result of differences in dehydration tolerance.