Microvideo Camera Research Articles

Root growth dynamics and biomass input of four over-wintering herbaceous crops in boreal conditions

Root growth of winter wheat (Triticum aestivum L.), winter rye (Secale cereale L.), red clover (Trifolium pratense L.), and timothy (Phleum pratense L.) was recorded to evaluate the environmental potential of over-wintering crops in a Nordic agroecosystem. In a field experiment on Aquic Haplocryoll soil, root intensities (number of roots/area) were measured to 50 cm depth by minirhizotron microvideo camera technology over a two -year period (21 recording sessions). At anthesis, root biomass and morphological parameters were measured by destructive soil sampling and image analysis of washed roots. Winter cereal roots reached 50 cm depth as soon as the autumn of the seeding year. For both post-seeding years, timothy roots developed the most intensively in spring, while red clover had higher root intensity than timothy in late autumn. At anthesis, the crops were ranked timothy > red clover > winter wheat > winter rye according to root length density, surface area density, and biomass. Based on S:R ratios, red clover appears to offer the most intense carbon sink at 0–60 cm soil depth. Over-wintering crops had living roots in the subsoil both in late autumn and early spring, indicating potential to plant available nutrient uptake outside the growing season of annual crops.

Development and evolution of a robotic surgical technique for the treatment of thoracic outlet syndrome

ObjectiveWe describe the development and evolution of a surgical technique that uses the robotic da Vinci Surgical System (Intuitive Surgical, Inc, Sunnyvale, Calif) for the transaxillary approach to repair the disabling thoracic outlet syndrome (TOS). We report our patient outcomes associated with the use of this robotic technique. MethodsWe present a retrospective review and analysis of data collected from a 16-year experience of a single surgeon using a robotic surgical system and technique for TOS surgery. From the initial design of an endoscope attached to a microvideo camera in 1982 to the adoption of the monorobotic arm with integrated voice in 1998, the main objective of the transaxillary approach has always been to improve visualization of congenital cervical anomalies of the scalene muscles. From February 2003 to December 2018, we performed 412 transaxillary decompression procedures using the robotic da Vinci Surgical System. The surgical procedure has been described in further detail and includes the following steps: (1) positioning of the patient into a lateral decubitus position and using a monoarm retractor; (2) creation of a mini-incision in the axillary area and creation and maintenance of the subpectoral anatomic working space; (3) placement of endoscopic ports and engagement of the robotic instrumentation; (4) dissection of extrapleural and intrapleural soft tissue; (5) creation of the “floater” first rib; (6) excision of the cervical bands and first rib; and (7) placement of thoracostomy tubes for drainage and closure of the incisions. ResultsNone of the patients died, and no patient experienced permanent neurovascular damage of the extremity. Of the 306 patients, 22 (5% of 441 operations) experienced complications. One patient developed postoperative scarring that required a redo operation with a robotic-assisted transaxillary approach. ConclusionsWith its three-dimensional visual magnification of the anatomic area, the endoscopic robotic-assisted transaxillary approach offers safe and effective management of disabling TOS symptoms. The endoscope facilitates observation of the cervical bands and the mechanism (pathogenesis) of the neurovascular compression that causes TOS, thereby allowing complete excision of the first rib, cervical bands, and scalene muscle. We sought to develop and perfect this robotic approach. The present study was not intended to be a comparative study to nonrobotic TOS surgery.

Structure and function of the large pronotal horn of the sand‐living anthicid beetleMecynotarsus tenuipes

AbstractLarge insect horns function as antipredator armaments, digging implements and intraspecific combat weapons. The sand‐living anthicid beetleMecynotarsus tenuipespossesses a large horn on the pronotum. Allometric relationships between body size and horn size did not show either a slope of more than 1 or sexual dimorphism, suggesting another function of the horn other than sexual selection via combat. Behavioral observation of individuals using a microvideo camera indicated that the horn is used to dig and move forward in loose sand. Only the hornedM. tenuipescould dig into sand, in contrast to the hornless anthicid beetlesStricticollis valgipesandClavicollis fugiens, which could not dig. When moving in sand,M. tenuipesjoins its pronotal horn and head to form a conical shape, with which it pierces into the sand. Then, it opens its horn and head outward to create a space in the sand for forward motion. Although it can dig deeply into sand by repeating these behaviors sequentially, digging speed tends to slow with depth, probably because the weight of the substrate increases.

Breeding Ecology of the Altamira Oriole in the Lower Rio Grande Valley, Texas

AbstractDuring 2002–2003, we studied the breeding ecology of the Altamira Oriole (Icterus gularis), a permanent resident that builds pendulous nests in remnant tracts of Tamaulipan brushland in the Lower Rio Grande Valley, Texas. We found 76 active oriole nests, seven of which were reused for second broods, for a total of 83 nesting attempts. Nearly 20% of the breeding individuals in our sample were subadults (second-year orioles). Using a microvideo camera, we were able to estimate incubation and nestling periods of 12.5 and 15.5 days, respectively. Fifty-nine percent of nests fledged at least one young, with successful nests averaging 2.3 fledglings. Failed nests were all intact, indicating that predators entered through the small opening in the top of the nest. Six nests fledged Bronzed Cowbirds (Molothrus aeneus), although two of these nests produced orioles as well. Vegetation analysis suggested that orioles preferred the tallest trees in the study sites in which to place their nests. A greater number of fallen logs was also a predictor of nest sites, which agrees with previous studies suggesting that orioles prefer open woodlands and edges. Formerly vast, dense forests in the Lower Rio Grande Valley have degraded into open woodlands, perhaps benefiting Altamira Orioles during the last 50 years. However, because of the oriole's preference for tall trees, continued degradation of forested tracts may not be beneficial to this species.

BREEDING ECOLOGY OF THE ALTAMIRA ORIOLE IN THE LOWER RIO GRANDE VALLEY, TEXAS

Abstract During 2002–2003, we studied the breeding ecology of the Altamira Oriole (Icterus gularis), a permanent resident that builds pendulous nests in remnant tracts of Tamaulipan brushland in the Lower Rio Grande Valley, Texas. We found 76 active oriole nests, seven of which were reused for second broods, for a total of 83 nesting attempts. Nearly 20% of the breeding individuals in our sample were subadults (second-year orioles). Using a microvideo camera, we were able to estimate incubation and nestling periods of 12.5 and 15.5 days, respectively. Fifty-nine percent of nests fledged at least one young, with successful nests averaging 2.3 fledglings. Failed nests were all intact, indicating that predators entered through the small opening in the top of the nest. Six nests fledged Bronzed Cowbirds (Molothrus aeneus), although two of these nests produced orioles as well. Vegetation analysis suggested that orioles preferred the tallest trees in the study sites in which to place their nests. A greater numb...

Studying aggression in school children: The use of a wireless microphone and micro‐video camera

AbstractThis paper describes a wireless microphone and micro‐video camera used successfully by the present authors to study direct, indirect, and relational forms of aggression in schools. Two major advantages of this equipment are identified; first, it avoids some of the potential biases and difficulties associated with the other methods and, second, it allows researchers to record and analyze a large number of significant variables that may otherwise be difficult to assess. The importance of this kind of data is discussed in relation to the development of effective interventions aimed at reducing aggression in schools. Aggr. Behav. 28:356–365, 2002. © 2002 Wiley‐Liss, Inc.

Root Length Growth of Eight Crop Species in Haplustoll Soils

Quantifying the dynamics of root growth is necessary for knowledge about development of rhizoplane and rhizosphere structure, and will indicate potentials for soil C sequestration and for water and nutrient usage. Root growth was measured during 3 yr in spring wheat (Triticum aestivum L.) on fallow and in seven crops in spring wheat–winter wheat–alternative crop rotation under minimum tillage on Wilton silt loam (fine silty, mixed, superactive, frigid Pachic Haplustolls). Two types of minirhizotrons (standard [Stand MR] and pressurized‐wall [P‐wall MR]) were read with a microvideo camera. Average maximum rooting depths fell into agronomic groups: oilseeds safflower (Carthamus tinctoris L.), 1.64 m, and sunflower (Helianthus annuus L.), 1.45 m; spring wheat, 1.31 m; mustard family crops crambe (Crambe abysinnica Hochst. ex R. E. Fr.), 1.17 m, and canola (Brassica rapa), 1.13 m; and legumes dry bean (Phaseolus vulgaris L.), 1.00 m, soybean [Glycine max (L.) Merr.], 0.99 m, and dry pea (Pisum sativum L.), 0.99 m. Median depths of root length growth ranged from 0.92 m for safflower to 0.46 m for dry bean, and ratios of median to maximum depths averaged 0.51. Six out of eight crops showed greatest rooting depths in relatively wet 1995, likely because of wetter subsoil. Greatest total root length in safflower, crambe, canola, soybean and dry bean occurred in drier‐than‐average 1997, which is interpreted as a response to soil water deficit. Results indicate that diverse crop rotations have the potential to utilize water and nutrients and input C over different soil profile positions than spring wheat‐based monocropping.

Root Length Growth of Eight Crop Species in Haplustoll Soils

Quantifying the dynamics of root growth is necessary for knowledge about development of rhizoplane and rhizosphere structure, and will indicate potentials for soil C sequestration and for water and nutrient usage. Root growth was measured during 3 yr in spring wheat (Triticum aestivum L.) on fallow and in seven crops in spring wheat–winter wheat–alternative crop rotation under minimum tillage on Wilton silt loam (fine silty, mixed, superactive, frigid Pachic Haplustolls). Two types of minirhizotrons (standard [Stand MR] and pressurized-wall [P-wall MR]) were read with a microvideo camera. Average maximum rooting depths fell into agronomic groups: oilseeds safflower (Carthamus tinctoris L.), 1.64 m, and sunflower (Helianthus annuus L.), 1.45 m; spring wheat, 1.31 m; mustard family crops crambe (Crambe abysinnica Hochst. ex R. E. Fr.), 1.17 m, and canola (Brassica rapa), 1.13 m; and legumes dry bean (Phaseolus vulgaris L.), 1.00 m, soybean [Glycine max (L.) Merr.], 0.99 m, and dry pea (Pisum sativum L.), 0.99 m. Median depths of root length growth ranged from 0.92 m for safflower to 0.46 m for dry bean, and ratios of median to maximum depths averaged 0.51. Six out of eight crops showed greatest rooting depths in relatively wet 1995, likely because of wetter subsoil. Greatest total root length in safflower, crambe, canola, soybean and dry bean occurred in drier-than-average 1997, which is interpreted as a response to soil water deficit. Results indicate that diverse crop rotations have the potential to utilize water and nutrients and input C over different soil profile positions than spring wheat-based monocropping.

Sclerotial formation and strand growth of Phymatotrichopsis omnivora in minirhizotrons planted with cotton at different soil water potentials

In situ strand growth and sclerotium formation of Phymatotrichopsis omnivora were observed in minirhizotrons using a microvideo camera. Strand growth was greater in soils subject to decreasing levels of soil matric potential (high water stress) compared with a continuously wet treatment. Intermediate levels of water stress (−0.5 to −0.9 MPa) resulted in less strand growth than either the dry or wet treatments. In all treatments strand growth increased to a maximum within 10 days of inoculum placement in soil but then declined to approach an apparent steady‐state value. The effects of soil matric potential on sclerotium formation were apparent when barley seeds were sown in the experimental units 3 weeks after the experiment had begun, permitting differential water cycling patterns to be obtained. Sclerotia were recovered in larger numbers from experimental units in which high water potentials (> −0.2 MPa) occurred 2 weeks prior to and following the death of host plants.

Minirhizotron Observation of Pigeonpea Root System after Waterlogging.

The root growth of pigeonpea plants [Cajanus cajan (L) Millsp.] was studied with a micro-video camera inserted into a glass tube embedded in the soil, and the effects of soil waterlogging were quantified. Daily changes in root length density (RLD) and the differences in root growth between waterlogged and control plants were calculated by adopting curve-fitting into the time-course data of RLD. Roots which suffered from waterlogging exhibited higher daily changes in RLD during the recovery process than unstressed roots. After waterlogging, an increase in RLD was first observed in the upper soil layers, and then in progressively deeper layers. This study demonstrates that root growth can be successfully studied by frequent observations of the same soil-plant interface through glass tubes. Furthermore, the effects of waterlogging can be adequately studied using this technique.

Conservation Tillage Affects Root Growth of Dryland Spring Wheat under Drought

In dryland cropping, no-tillage can increase small grain crop growth compared with conventional tillage. Because root systems develop ahead of aboveground growth and are affected by soil environment, observation of root growth will show the mechanisms by which no-till enhances crop growth. Wheat (Triticum aestivum L.) was grown in a spring wheat-winter wheat-sunflower (Helianthus anuus L.) rotation begun in 1984 on Temvik-Wilton silt loam (fine-loamy, mixed Typic and Pachic Haploborolls) under conventional till (CT : spring disking), minimal till (MT : spring undercutting) and no-till (NT). Root length growth (RLG) was measured by microvideo camera in pressurized-wall minirhizotrons, and soil water was measured by neutron moisture meter. Relative to CT, NT generally enhanced RLG more than aboveground growth ; RLG averaged 65, 130, and 145 km/cm 2 in 1988, 1989, and 1990, respectively. In 1988, RLG was 37% greater than MT (P < 0.1), with CT intermediate. In 1989, RLG was 40% greater in NT than in CT, with MT intermediate, and RLG in 1990 was 112% greater in NT than CT (no MT). Final biomass averaged 380, 1730, and 3090 kg/ha in 1988 through 1990, and was 36% greater, not significantly different, and 44% greater in NT than CT, respectively. Root penetration was shallow (1.1 m or less) in dry subsoil, but in each year roots penetrated to greater soil depths under NT than under MT or CT. Amounts of stored soil water were generally not significantly different among tillages, but more water was depleted in 1990 under NT than CT. Cooler soil under NT (measured in 1989) and superior soil water conservation in the near-surface zone appear to confer a root growth advantage to the NT treatment.

Fine Root Dynamics of Alfalfa after Multiple Cuttings and During a Late Invasion by Weeds

AbstractThe dynamics of fine root systems for alfalfa (Medicago sativa L.) during seasonal harvests are important for plant regrowth, yet they are not well understood. The primary objective of this study was to determine fine root responses to multiple cuttings of an alfalfa crop for a 5‐yr period and during an invasion of companion weed plants during the last 2 yr of the study. Root development, distribution, and turnover rates were evaluated by minirhizotron (MR) and microvideo camera methods on a Kalamazoo loam (fine‐loamy, mixed, mesic Typic Hapludalfs). The development and distribution of alfalfa fine roots were modified more by season and age of the plants than by defoliation. New root development occurred primarily in the spring and immediately following rainfall interruptions of extended dry periods. Spatial accumulations of roots were observed at the interface of the Bt and 2Bt soil horizons, which also accumulated water and nutrients. More roots died with the progression of each season, especially when plants were 3 to 5 yr of age. New root growth decreased and root death rates increased at soil depths from 0 to 1.1 m, during the period between cuttings from July and August 1993 in the aging alfalfa stand, whose active region of root growth exceeded the depths of the MR observation tubes. New alfalfa root growth appeared at progressively greater depths, especially after 3 yr of cropping. Therefore, mature alfalfa root systems should be sampled to soil depths greater than 1 m. Root systems of encroaching weeds appeared to accumulate in the 0‐ to 0.6‐m region of the soil profile.

Turfgrass Root Systems Evaluated Using the Minirhizotron and Video Recording Methods

Nondestructive evaluations of turfgrass root systems have been limited to large rhizotrons. Recent developments in the minirhizotron and associated microvideo camera technologies provide opportunities for quantifying in situ root systems of turfgrass field plots. Minirhizotron root counts were compared with destructive core sampling for root length and weight densities of ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.) grown under putting green and fairway conditions, and annual bluegrass [Poa annua L. var. reptans (Hausskn.) Timm] grown under fairway conditions. Correlations between minirhizotron root counts and root length density (cm root/cm3 soil), minirhizotron root counts and root weight density (mg root/cm3 soil), and root weight density and root length density (r2 = 0.861, 0.843, and 0.955, respectively) were very highly significant when data were combined across all depth zones for an October sampling of the bentgrass green. Total root numbers observed along minirhizotrons were greatest early in the growing season, followed by a decline during July. Annual bluegrass root measurements were lower than either of the creeping bentgrass turfs. The root system of the creeping bentgrass turfs recovered during late summer, whereas the annual bluegrass turf showed little recovery from summer root decline. Data indicated that minirhizotron estimates provided an acceptable means for characterizing the profile distribution of turfgrass root systems from the soil surface to 300 mm, and possibly deeper into the soil profile.

A new model for in vivo observation of the feline spinal microcirculation: the closed spinal window.

A new experimental model is described that uniquely allows the in vivo observation and quantification of vascular caliber changes on the dorsal surface of the feline spinal cord. The model consists of a rectangular Plexiglas window that is sutured to the lumbar dura and is supported by a special holder. Inlet and outlet tubes attached to the window serve for topical applications of mock cerebrospinal fluid or vasoactive agents to the surface of the cord and for continuous monitoring of intrathecal pressure. Pial vessels below the window were observed at 200-fold magnification with the aid of a microvideo camera. Spinal arterioles reacted to hypercarbia and superfusion with acetylcholine solution in a manner similar to cerebral arterioles. Tests with increased intrathecal pressure showed that the window remained watertight between 25 and 130 mm Hg, with an average leakage pressure of 57.8 +/- 33.5 mm Hg. To promote the use of this model in other laboratories, the authors give a detailed description of the closed spinal window preparation and report their experiences gained from 50 experiments. It is concluded that the closed spinal window is a highly reproducible model, suitable for the study of the feline spinal microcirculation for several hours in vivo.