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The revolution in high-throughput omics technologies has dramatically expanded our understanding of the epilepsies as complex diseases. It is now clear that further progress in treating the full spectrum of seizure disorders requires a systems-level framework for analyzing and integrating data from multiple omics technologies that moves beyond the search for single molecular alterations to an understanding of dysregulated pathways in epilepsy. Taking such a pathway-centered view requires further integrating the tools of systems biology into epilepsy research. In this appraisal, we highlight and summarize systems biology approaches in basic epilepsy studies as they were discussed during the 2017 Workshop on the Neurobiology of Epilepsy (WONOEP). During the 3-day event, participants exchanged emerging results and thoughts on developing the systems biology of epilepsy, and the promise and limitations of these approaches for the near term.

The transboundary St Mary River drains Glacier National Park, USA, and was progressively dammed and diverted over the 20th century to support agricultural irrigation in northern Montana and southern Alberta, Canada. Following reduced instream flows, the riparian cottonwoods collapsed, and by 2000, few parental trees remained to provide seeds for cottonwood replenishment. As a novel twofold restoration strategy we: (1) worked with the dam operators to deliver a functional flow regime, a regulated instream flow pattern intended to recover some ecological function and specifically seedling recruitment, and (2) delivered cottonwood seeds by direct spreading and by sticking cuttings with seed catkins to allow gradual seed dispersal. The combination of river regulation and seeding enabled cottonwood colonization, and around 1.5% of the applied seeds produced seedlings after the first summer, at sites without livestock or heavy recreational use. Around 15% of those seedlings survived through the fourth summer, with mortality due to drought stress and flood scour, and establishment and survival were higher for the prairie cottonwood, Populus deltoides, than the narrowleaf cottonwood, Populus angustifolia. This study confirmed that the lack of seed source trees limited cottonwood colonization and demonstrated that the twofold restoration strategy provides promise for severe situations where parental trees have been lost. However, this would require substantial effort, and it would be more efficient to provide survivable instream flow patterns that avoid cottonwood collapse. Copyright © 2015 John Wiley & Sons, Ltd.

Cottonwoods are poplar trees that are well adapted to dynamic riparian, or streamside, zones throughout the Northern Hemisphere. Here we assess the influences of three prominent physical disturbances, floods, fire, and ice, on cottonwood population ecology. We emphasize cottonwoods along rivers from the “Crown of the Continent”, the central Rocky Mountain zone around the Canada – United States border, where five Populus species overlap and four hybridize. Moderate to major floods scour banks and deposit bars, creating barren and moist colonization sites that are essential for cottonwood seedling recruitment. Floods also scarify shallow roots, thus promoting clonal suckering, especially for the section Tacamahaca species: narrowleaf cottonwood ( Populus angustifolia James), balsam poplar ( Populus balsamifera L.), and black cottonwood ( Populus trichocarpa Torr. & A. Gray). Fire would naturally be less frequent in some riparian zones because of the moist conditions and firebreaks provided by the streams, but with human use, floodplain forest fires have probably increased. Following fire, regrowth through clonal root and shoot suckers can be prolific for the Tacamahaca species, but is limited for the section Aigeiros , prairie cottonwood ( Populus deltoides Bartr.). River ice, and especially ice drives that accompany winter or spring break-up, provide powerful riparian disturbances that have often been neglected. Ice drives generate barren sites for seedling colonization, shear shoots, and scarify roots promoting shoot and root suckering, and sever branches, enabling dispersive clonal branch propagation. Following studies along many regional rivers, we conclude that: (i) riparian cottonwoods are tolerant of, and dependent upon, occasional physical disturbance for population rejuvenation; (ii) differing disturbance responses contribute to niche differentiation across the Populus species; (iii) different disturbances enable varied spatial and temporal patterns of cottonwood establishment, including fringe, general, and patch recruitment; and (iv) natural disturbance regimes probably favor native cottonwoods and disfavor some invasive, woody plants. River damming and flow regulation often attempt to attenuate flood and ice disturbance, a management objective that may hinder the perpetuation of native floodplain forests. We recommend that river resource managers seek to allow flood and ice disturbance, and additionally, fire may provide a managed disturbance that could rejuvenate overmature cottonwood groves along some regulated rivers.

A major flood in June 1995 along most streams in southern Alberta (AB) and southeastern British Columbia (BC), Canada, permitted the comparison of natural seedling establishment of different cottonwood species across different environments. Nine study sites were established along a 340-km corridor from BC, over the Rocky Mountain Continental Divide, and onto the foothills and then prairies of AB. Four native cottonwood species occurred from BC to AB: the black cottonwood, Populus trichocarpa Torr. and Gray, balsam poplar, P. balsamifera L., and narrow-leaf cottonwood, P. angustifolia James, of section Tacamahaca, and the prairie cottonwood, Populus deltoides Bartr. ex Marsh, of section Aigeiros. Cottonwood seedlings of the 1995 cohort were monitored from 1995 through 1998 in quadrats along riparian transects. The study confirmed that a major flood enabled extensive cottonwood recruitment along mountain, foothills, and prairie river reaches and revealed that both, environment and species influenced cottonwood seedling growth in situ. Across the sites, seedling heights varied ten-fold and were closely negatively correlated with site elevation (1995: n = 9, r2 = 0.93; 1997: n = 4, r2 = 0.92). The increased growth at lower elevations was probably associated with warmer temperatures and a longer growing season; seedling growth was positively correlated with the accumulation of growing degree days of nearby weather stations (1995: n = 6, r2 = 0.88). Growth rate was also influenced by species as height varied up to three-fold across species at sites where species co-occurred. P. deltoides seedlings grew fastest followed by P. trichocarpa/P. balsamifera and intersectional hybrids and, finally, P. angustifolia and intrasectional hybrids. The superior seedling growth of P. deltoides is consistent with its life history and distribution. P. deltoides occurs along prairie river reaches with warmer and drier climates and higher-order streams with finer substrate textures; these physical conditions would favor seedling recruitment. The alternate environmental conditions of foothillls and mountain regions probably encourage clonal (asexual) recruitment that may supplement seedling recruitment, particularly for the Tacamahaca species.

Cottonwoods occur in riparian areas where water table depth generally varies with the elevation of the adjacent river. Plant adaptation to the riparian zone requires the coordination of root elongation to maintain contact with the water table during the summer decline. We investigated the effects of rate of water decline on growth allocation and concentrations of endogenous gibberellins (GAs) in black cottonwood (Populus trichocarpa Torr. & A. Gray ex Hook.) saplings. Rhizopods were used to achieve water decline rates of 0, 2 and 4 cm day −1 . Root elongation approximately doubled in response to the 2 cm day −1 treatment, whereas leaf area was reduced. A water decline rate of 4 cm day −1 led to water stress, as evidenced by reduced growth, increased leaf diffusive resistance, decreased water potential, and leaf senescence and abscission. Endogenous GAs were extracted, purified and analyzed by gas chromatography-selected ion monitoring with internal [ 2 H 2 ]GA standards. Across the sampled plant organs, GAs were generally highest in shoot tips and sequentially lower in basal stems, root tips, leaves and upper roots; GAs were thus abundant in rapidly growing tissues. Of the GAs measured, GA 1 tended to predominate, followed sequentially by GA 3 , GA 8 , GA 19 , GA 20 , GA 29 and GA 4 . There was little relationship between GA concentration and growth allocation across the water table decline treatments, although GA 8 was consistently reduced in plants experiencing water table decline. Because GA 8 is the final gibberellin in the metabolic sequence, it might be useful for assessing historic patterns of GAs and growth rate. This study demonstrated changes in growth allocation in response to water table decline, but provided little evidence that endogenous GAs play a primary role in the regulation of root elongation in response to water table decline.

Following heavy rain in early June 1995, flows of the Oldman River in Alberta, Canada were the highest on record (since 1911). This ‘flood of the century’ preceded cottonwood seed release, and created suitable sites for seedling establishment. After the flood peak, the Oldman River Dam and tributary dams were operated to deliver a relatively natural and gradual river stage recession of about 2.5 to 5 cm per day. Nine research sites were established on lateral and point bars to study establishment, survival, and growth of seedlings ofPopulus angustifolia, P. balsamifera. andP. deltoides. In 1995, transects were established perpendicular to the river to the zone of mature cottonwoods; 131 quadrats were established at positions along the transects that intersected cottonwood seedling bands and revisited in 1996 and 1997. At all sites, extensive areas of seedlings occurred in 1995, and seedling bands ranged in elevation from 0.6 to 4 m above the late summer stream stage. Low elevation seedlings were removed in 1996 and 1997 by ice and water scouring; high elevation seedlings died primarily due to drought stress. Seedlings that survived through 1996 and 1997 occurred at elevations ranging from 1.7 to 3 m, but seedlings above 2.5 m grew slowly. Within the seedling bands, densities after the first season ranged from 80 to 4,000 seedlings m−2, and densities fell to about 10% and then about 5% over the second and third years, respectively. The seedlings averaged only 2 cm in height after 1995 and increased to about 8 and 25 cm in 1996 and 1997;P. deltoides seedlings were larger than those of the other species, with some reaching 1 m in 1997. Thus, a major flood enabled a massive cottonwood seedling recruitment event that commenced in the flood year. The extensive recruitment occurred along a dammed river and was probably promoted deliberately by gradual stream stage decline after the flood peak.

This paper describes the ‘recruitment box,’ an integrative model that defines the stream stage patterns that enable successful establishment of riparian cottonwood seedlings. In western North America, cottonwood seed dispersal generally occurs after annual peak river flows. The receding stream exposes moist sites upon which seeds land after transport by wind and water. Germination is rapid, and initial seedling establishment is often prolific. However, the vast majority of seedlings die, primarily due to drought stress, as root growth is insufficient to maintain contact with the receding zone of moisture. Cottonwood roots grow about 0.5 to 1 cm per day or 60 to 100 cm in the first year. Along the ‘losing’ streams in semi-arid regions, the riparian water table is an almost horizontal extension from the stream stage. A capillary fringe exists above the water table and is often 30 to 40 cm in elevation, but can range from about 5 to 130 cm depending on substrate texture. The combination of root growth and capillary fringe define the successful recruitment band, which is usually from about 0.6 to 2 m in elevation above the late summer stream stage. Within this range, higher elevation establishment occurs (i) for theAigeiros cottonwoods,Populus deltoides, andP. fremontii, which grow more rapidly thanTacamahaca species and occur in warmer areas with longer growing seasons; (ii) along larger rivers that are characterized by more gradual stage fluctuations; and (iii) along streams with finer substrate. The rate of stream stage decline is also critical for seedling survival and should not exceed 2.5 cm per day. The recruitment box model is consistent with dendrochronological interpretations that moderate flood events are naturally required for cottonwood recruitment. Flood events with recurrences of about 1 in 5 to 1 in 10 years often satisfy the model and provide stream stage patterns with a gradual decline through the recruitment box. The model will facilitate analyses of the reproductive ecology of riparian cottonwoods and also permit the prescription of stream stage patterns for cottonwood seedling recruitment along dammed rivers.

The influence of rate of water table decline was studied with three North American cottonwood (poplar) species: the prairie cottonwood, Populus deltoides ; the narrowleaf cottonwood, P. angustifolia ; and the balsam poplar, P. balsamifera . Shoot cuttings were rooted and transplanted into rhizopods, experimental devices that permit the controlled manipulation of water table depth. Three rates of water table decline were applied, 0, 4 and 10 cm day −1 , and growth and transpiration were studied. Two clones of each species performed relatively similarly; the P. balsamifera clones grew fastest under all three treatments, followed by P. deltoides under 0 and 4 cm day −1 conditions. Under the 10 cm day −1 treatment, the P. deltoides grew as slowly as P. angustifolia . In all genotypes, shoot growth and apparent transpiration were progressively reduced with increasing rate of water table decline. Conversely, root growth was promoted by water table decline and root elongation was most rapid under the gradual 4 cm day −1 treatment; root elongation was insufficient for the abrupt 10 cm day −1 decline and some P. angustifolia and P. deltoides saplings died under that treatment. The present study demonstrates that tolerance to water table decline varies across cottonwood genotypes and that P. balsamifera saplings were the most vigorous. This is relevant to the natural distribution in which P. balsamifera occurs in mountain regions where stream stages and riparian water table depths often change abruptly. The vigor of P. balsamifera is also consistent with the reproductive mechanism of `branch propagation', a process of clonal recruitment in which browsed or broken branch fragments root along stream edges, enabling dispersive propagation, particularly of P. balsamifera and P. trichocarpa .

Completed in 1951, the St. Mary Dam enables water storage and diversion for irrigation; river flows downstream are consequently dramatically reduced during summer months. To assess historical changes in the abundance of riparian cottonwoods (Populus balsamifera, Populus angustifolia, and a few Populus deltoides), airphoto analyses were conducted for 40-km river reaches upstream and downstream from the dam and along adjacent dammed and undammed rivers. Cottonwoods along the lower St. Mary River are confined by steep-walled canyons to narrow bands and consequently analyses of the lineal river distance associated with cottonwoods were conducted. These revealed a 68% decline from 1951 to 1985. The decline was progressive, with 28.9, 27.6, 15.1, and 7.6% of the reach associated with cottonwoods in 1951, 1961, 1981, and 1985, respectively. Ground surveys from 1985 to 1994 indicated further decline after 1985 and an absence of cottonwood seedlings and saplings. Cottonwood stands upstream from the St. Mary Dam and along adjacent rivers are more extensive and analyses of the areal extent of stands were consequently appropriate. These indicated minor change along the upper St. Mary (−0.5%), the upper (+1.9%) and lower Waterton (+3.5%), and the upper Belly (−9.1%) rivers, and an increase in forest abundance along the lower Belly River (+52.2%), between 1951 and 1985. Thus, the decline of cottonwoods along the lower St. Mary River was not symptomatic of a general pattern of decline in the region. Analyses of historical stream flows indicated that the cottonwood mortality was drought induced as a result of insufficient flows during the hot, dry summer periods and abrupt flow reductions following the high-flow period in the late spring. The riparian water table was determined to be closely coordinated with river stage, as changes in river elevation were followed by quantitatively similar changes in water table depth. Along the St. Mary River, reduced sedimentation downstream from the dam was not considered to be responsible for the cottonwood decline. The historically sparse cottonwood abundance along the lower St. Mary River may have reflected environmental conditions that were naturally only marginally suitable, and those groves may have been particularly vulnerable to the impacts of river flow regulation. Key words: Populus, cottonwoods, instream flows, mortality, riparian vegetation.

From 1990 to 1993, 690 small cottonwood saplings were excavated along four rivers in the Oldman River Basin to determine their method of origin. Overall, 52% began as seedlings while 48% originated through clonal mechanisms, of which 30% (of the total) were root suckers, i.e., adventitious shoots from preexisting roots, and 18% were shoot suckers, i.e., new shoots originating from buried shoots. The shoot suckers arose primarily through (i) flood training, i.e., new shoot emergence from young shoots that had been toppled and buried during flood events, and (ii) shoot regrowth following decapitation by ice scouring or animal browsing. Only two saplings originated through cladoptosis, propagation from excised shoot fragments. The proportion of seedlings versus clonally established shoots varied somewhat across years and sites. Within a site, saplings near the river's edge were more commonly seedlings, whereas saplings further from the river were more commonly root suckers. Three cottonwood species occurred in the forests studied and their reproductive strategies varied somewhat. Unlike the balsam poplar (Populus balsamifera), narrowleaf cottonwood (Populus angustifolia), and interspecific hybrids, the prairie cottonwood (Populus deltoides) did not propagate through root suckers; all species produced seedlings and shoot suckers. This study demonstrates that clonal reproduction has the potential to contribute to the regeneration of riparian cottonwood forests in southern Alberta. The contribution through clonal propagation complicates the forest population structure and should be considered in programs to conserve the remaining riparian cottonwood forests in southern Alberta and elsewhere in North America. Key words: Populus, cottonwoods, hybrid poplar, reproduction, clones, suckering, seedlings.

Researchers and clinicians have long argued that cognition is an important component of sexual arousal. We tested the hypothesis that self‐schema activation is one of the cognitive processes involved in sexual arousal to audiovisual stimuli. College students (105 males and females) individually viewed an erotic videotape that contained 20 66‐millisecond presentations of various trait adjectives, which students were asked to read aloud. About half of these students had performed a self‐reference task (i.e., made judgments regarding the self‐descriptiveness of each word) prior to viewing the tape. Among students who had performed the self‐reference task, those reporting relatively high sexual arousal to the film correctly identified more words than students who reported little or no arousal. Among students who did not perform the self‐reference task, arousal had no effect on the number of words identified. This finding was tentatively interpreted as evidence that the self‐schema is activated during sexual a...

The effects of substrate texture and rate of water table decline on the growth of a Populus balsamifera x Populus deltoides hybrid were studied using rhizopods. Rooted shoot cuttings were transplanted into growth tubes filled with gravel, sand, or a 1:1 (v/v) mixture of sand and were treated with water level declines of 0, 2, 5 or 10 cm day−1. Water drained fastest from the gravel-filled tubes, intermediate in the mixture and slowest from the sand-filled tubes. The effects of rapid water table decline were most severe on plants grown in the gravel and least severe on those grown in sand. Transpiration, height, leaf number, leaf area and plant health decreased with increasing rates of water table decline and increasing gravel content in the substrate. The reduction in transpiration and plant growth indicates that rapid water table decline caused drought stress of the poplars. Root elongation was promoted in all substrates by water table decline. The results indicate that alterations to river flow that cause abrupt drops in riparian water table will retard the transpiration and growth of riparian poplars. These effects will be more severe along flood-plains with coarse substrates.

Although historically abundant, the riparian poplar forests of the western prairies are now endangered as a result of the damming and diversion of rivers in this region. Recent reports have described substantial declines of riparian poplar forests downstream from dams in Alberta, Canada; Montana, North Dakota, Wyoming, Colorado, and Arizona, USA. The present report analyzes the forest and hydrological conditions reported previously in order to clarify the causes of the downstream forest decline. Dams were found to contribute to forest failure by (1) reducing downstream flows and/or (2) altering flow patterns to attenuate spring flooding and/or stabilize summer flows. Reduced flows are reported to induce drought stress, which is particularly lethal to seedlings and very old poplars. The artificial moderation of spring flooding may inhibit the formation of seedbeds essential for seedling replenishment. Increased river valley development involving cattle grazing, agricultural clearing, and direct harvesting of trees also contributes to forest failure. Potential methods for mitigating the impacts of dams on downstream forests include downstream flow schedules that (1) retain occasional spring flooding, (2) taper off rather than abruptly drop downstream flow, and (3) provide adequate flows throughout the summer. Poplar forest stabilization and recovery can be further promoted by fencing to protect trees from livestock grazing and trampling, or artificial site preparation such as cultivation or scarification to encourage poplar regeneration.

River damming has dramatic environmental impacts and while changes due to reservoir flooding are immediate, downstream impacts are more spatially extensive. Downstream environments are influenced by the pattern of flow regulation, which also provides an opportunity for mitigation. We discuss impacts downstream from dams and recent case studies where collaborative efforts with dam operators have led to the recovery of more natural flow regimes. These restoration programs, in Nevada, USA, and Alberta, Canada, focused on the recovery of flow patterns during high flow years, because these are critical for riparian vegetation and sufficient water is available for both economic commitments and environmental needs. The restoration flows were developed using the “Recruitment Box Model”, which recommends high spring flows and then gradual flow decline for seedling survival. These flow regimes enabled extensive recruitment of cottonwoods and willows along previously impoverished reaches, and resulted in improvements to river and floodplain environments. Such restoration successes demonstrate how instream flow management can act as a broadly applicable tool for the restoration of floodplain forests.

Riparian poplar forests are declining downstream from many dams in the western prairie regions of North America. Drought-induced seedling and sapling mortality caused by abrupt drops in water table level following river flow regulation may be contributing to this forest decline. Here we describe a device, the rhizopod, for studying the influence of a changing water table on poplar seedling survival and growth. Seeds of a natural poplar hybrid (Populus deltoides x P. balsamifera) were planted in five rhizopods and treated to water table declines of 0, 1, 2, 4, or 8 cm day(-1). Each rhizopod consisted of 15 growth tubes connected to a central water reservoir through which the water level was regulated. Seedling survival was over 90% in rhizopods in which water table declined by 0, 1 or 2 cm day(-1), but was reduced to about 40% and less than 25% in rhizopods in which the water table level declined by 4 and 8 cm day(-1), respectively. Maximum shoot height, leaf number, and leaf area were observed in the rhizopod with a constant water table and decreased progressively with increasing rates of water table decline. Maximum root mass and length were observed in plants subjected to declines in water table level of 0 and 1 cm day(-1), respectively.

Forty-eight adult male volunteers attempted to suppress sexual arousal while viewing a sexually explicit videotape and generate an arousal response while viewing a neutral videotape. Attendance to the stimuli was assured by requiring subjects to provide an ongoing verbal description of the videotape they were viewing. While significant effects in controlling arousal were obtained, the degree of subject success varied as a function of the criteria used for evaluating outcome. The most conservative analysis, a simultaneous discriminant analysis procedure comparing subjects penile plethysmographic responses across the entire 3 min of each condition, revealed that in no case was a subject able to produce a pattern of sexual response that was misclassified as the condition he was attempting to emulate. Results support the value of requiring attendance to experimental stimuli and of analyzing trends/patterns of arousal across an entire experimental period in identifying attempts to “fake” sexual preferences. Theoretical and clinical implications of these findings are discussed.

Despite the prevalence of premature ejaculation and the success in its treatment, researchers have yet to offer a compelling, empirically based theory regarding its nature or etiology. This study explored a model that argues that anxiety may not be necessary for the existence of this dysfunction. Fifteen premature ejaculators (PEs) and 17 nonpremature ejaculators (NPEs) engaged in self-stimulation to orgasm both in the laboratory and at home. The following specific hypotheses were tested: Compared to NPEs, PEs would demonstrate (i) shorter orgasmic latencies, both in the lab and at home, and (ii) equally accurate estimates of these latencies. Results offered strong support for both hypotheses. These findings, and those derived from a questionnaire completed by subjects, were seen as consistent with a psychophysiologic model of premature ejaculation. According to this model, the role of anxiety is seen as variable, interacting with the somatic vulnerability of the individual to determine orgasmic latency.

Pregnancy among adolescents/young adults continues at epidemic levels despite widespread concern regarding its social and psychological consequences. Cognitive psychologists point out that active decisions and behaviors such as those involved in effective contraception are facilitated or inhibited by any of a number of relevant attitudes and beliefs. The present investigation examined several such cognitive variables. Specifically, the following hypotheses were tested: Among adolescents/young adults, the use of effective contraception would be positively related to (a) the number of known cases of unwanted pregnancy of which subjects were directly aware, and (b) sexual guilt. A sample of 147 sexually active single college students aged 18–19 provided information relevant to these hypotheses. Analyses indicated that contraceptive behavior was unrelated to the number of unwanted pregnancies of which subjects were aware, but was substantially and significantly associated with sexual guilt, even when the poss...