Abstract

There is an increasing interest in using ultrasonication in controlling

algal (cyanobacterial) blooms and biofouling, a physical method with presumably no

adverse effects on non-target organisms, such as fish and zooplankton. At the beginning

the use of ultrasound (US) to control algae and biofouling has focused on high-power

US causing cavitation; however, due to the potential damage to non-target organisms

including marine mammals and human divers, high-power US causing cavitation are

not used anymore for algae control in natural environment. Current ultrasonic algae

control devices use low-power and thus control algae and biofouling by utilising

resonance frequencies and the sound pressure caused by a sound wave propagating

through a water column. There are only few studies existing on the effect of US on

non-target organisms with incomplete information on wavelengths and intensities of

US devices. However, we can conclude that non-cavitation US devices used to control

algae and reduce biofouling had no adverse health effects on studied fish species with

no feeding and behaviour changes noticed. Caution should be taken when installing

US devices in marine locations since they may interfere with communication between

sea mammals or may cause adverse effects on fish from subfamily Alosinae, the only

known fish able to detect US. The studies dealing with non-cavitation US used to

control algae and biofouling on non-target zooplankton have conflicting results from

high mortality to no evident effects. Therefore, caution should be taken when using

US for counteract algal growth in ponds or lakes, especially in terms of zooplankton

and natural balance maintenance.

Keywords

algal blooms, algal control, fish, ultrasound, zooplankton

Abstract

The immune system is crucial to recognise and distinguish between self

and nonself, and react to challenges posed by the environment. We present a review

on the innate immunity of crustaceans, in particular terrestrial crustacean woodlice

Porcellio scaber . The main effectors of immunity in crustaceans are haemocytes which

carry out the cellular immune processes and synthesise humoral defence components.

We described three types of haemocytes in P. scaber : semigranulocytes (65% of freely

circulating haemocytes), granulocytes (17%) and hyalinocytes (18%). The average

density of free circulating haemocytes is 3.50 ± 0.19 x 10 6 cells/mL. Semigranulocytes

and granulocytes are both oval shaped with a similar diameter (11.2 ± 0.4 μm and 12.0

± 0.3 μm, respectively), but granulocytes have a higher density of granules which are

also larger than in the case of semigranulocytes. Hyalinocytes are round, agranular

and smaller (8.1 ± 0.3 μm). Two types of hyalinocytes were discovered. One subtype

is of particular interest, as it has a very large nucleus with dominating euchromatine

resembling properties of the stem progenitor cells. We have implemented new methods

to measure humoral components in the haemolymph of P. scaber . These are:

phenoloxidase like activity, nitric oxide levels, antioxidant enzyme activity and alpha-

2-macroglobulin. The formation of nodules was noted in the case of P. scaber infection

with bacteria Rhabdochlamydia porcellionis . Our future research will be focused to

investigate the immune response of P. scaber at the proteome and transcriptome level.

Keywords

encapsulation, haemocyte, melanization, nodulation, phagocytosis, signal pathway

Abstract

Dormouse fat continues to be used in traditional medicine to alleviate

various health problems but, to date, there has been no systematic research into its role

as an antimicrobial agent. Microorganisms have been confirmed as being present both

in fresh dormouse fat, that has been produced in a traditional way and in previously

applied fat. When studied in vitro, dormouse fat showed no inhibitory effect on the

growth of the indicator bacteria Escherichia coli and Staphylococcus epidermidis . The

apparent antimicrobial efficacy attested by its continuing and seemingly successful

use in traditional medicine is most likely related to stimulation of the host immune

system. Further research is needed to investigate and confirm the usefulness of dormouse

fat, or its active components, in the treatment of infections related to multiple

resistant microbial strains.

Keywords

antimicrobial activity, dormouse fat, microorganisms

Abstract

Alpine plants have evolved strategies to survive harsh conditions,

which include high UV and visible radiation, extreme temperatures, dryness and lack

of nutrients. Survival strategies include biochemical, physiological and morphological

responses, which are scarcely studied because of the time-demanding and complex

experimental conditions. We researched functional traits in the alpine plant common

rockrose Helianthemum nummularium subsp. grandiflorum growing under ambient

UV-B and reduced UV-B radiation at different altitudes (1600 and 2000 m a.s.l.) of

mount Vogel in the Slovenian Alps. Leaf anatomy, pigments and optical properties

were investigated at the beginning and at the end of the growing season. Plants showed

high constitutive UV-absorbing compounds content (UV-AC) throughout the season.

Most leaf thickness parameters were not altered according to UV and altitude conditions.

Leaves did not transmit any UV spectrum, in agreement with high UV-AC.

High photosynthetic spectrum transmittance at alpine altitudes was due to complex

biochemical and anatomical responses to these conditions, rather than to UV radiation.

Unchanged chlorophyll content of H. nummularium could be related to shrub life form,

where leaves shade out high UV and PAR irradiance as well as contribute to lower

leaf temperature. This study shows the complexity of alpine plant response, where

specific characteristics of plant species should not be overlooked.

Keywords

Helianthemum nummularium , leaf optical properties, pigments, UV radiation

Abstract

The interaction of bark with light depends on the optical properties of

the bark, which are important for plant energy balance especially out of the vegetation

season. Light reflected from bark also represents a kind of “bark spectral signature”

that may be species-specific. This study examines some morphological, biochemical,

and physiological traits that may affect the reflectance of the bark of 1-year-old twigs

of different shrubs: Corylus avellana , Rosa canina , Ligustrum vulgare , Sambucus nigra ,

Cornus sericea var. flaviramea , and Viburnum lantana . High variability was seen

across these species for morphological, biochemical, and physiological traits, except

for photochemical efficiency of photosystem II. The bark spectral signatures differed

significantly across these species. The reflectance peak for C. sericea var. flaviramea

was in red, for C. avellana in green, and the other species showed a wide peak from

green to red light. Redundancy analysis revealed that UV-B–absorbing substances and

anthocyanin content, along with outer and inner bark thickness, together explained

61% of the reflectance spectra variability. Outer bark thickness was important for

reflectance in UV, violet, and blue, while anthocyanins were important for reflectance

in green and yellow. Chlorophyll b was negatively related to the reflectance of visible

light. This study revealed great importance of biochemical traits for explaining bark

reflectance. Differences in “bark spectral signatures” enable differentiation across

species out of the vegetation season.

Keywords

bark, pigments, reflectance, UV-B–absorbing substances, woody plants

Abstract

This research investigated crown ratio models for Tectona grandis

plantation in Oluwa Forest reserve (Ondo State, Nigeria) using variables of slenderness

coefficient and merchantable height. With three non-linear regression functions - logistic,

Chapman-Richard and exponential we showed that basal area, tree stem volume

and mean tree height per hectare were of high significance. In the same vein, there

were fewer tree species in the class of higher diameter and height than there were in

lower class. There were also more trees in the co-dominant and intermediate classes

than in the dominant and suppressed layers. The lack of emergence in the plantation

reflected the past disturbance of the ecosystem. Most of the tree growth variables

were significantly different in different canopy layers in the study area. Based on the

evaluation models, the three functions investigated for tree crown ratio modeling gave

constant and reliable results in all canopy layers considering their indices. Especially,

Chapman-Richard and exponential functions gave consistent trends and good fits for

crown ratio models. It is recommended to put strict measures in place to avert any

level of illegalities that may likely disrupt the delicate equilibrium of the ecosystem. It

is also recommended that complexity revealed in this study is sustained in the region,

and encouraged in other parts of Nigeria.

Keywords

crown ratio, modeling, Oluwa forest reserve, Tectona grandis, tree growth