Giant Paleodictyon in Eocene flysch

A giant Paleodictyon gomezi with a maximum mesh diameter of 13 cm and covering more than 0.5 m² occurs in the lower Eocene flysch near Zumaya. The giant Paleodictyon occurs with flute casts and, therefore, must have been produced deeply in the sediment. The lengthening of mesh cells parallel and perpendicular to the flute casts implies changing current directions during trace production. Rows of elongate and offset mesh cells reflect the row-by-row production of the trace; however, the base line followed by the trace fossil producer (meandering or spiral) cannot be reconstructed because of incomplete preservation. The extraordinary size of this giant Paleodictyon contradicts the evolutionary trend of deep-sea trace fossils toward optimization and miniaturization, since similar large Paleodictyon specimens occur in Silurian flysch.     

Ultrastructure and development of the rhabdomeric eyes in Lineus viridis (Heteronemertea, Nemertea)

Nemerteans are undoubtedly members of the Spiralia, although their phylogenetic relationships are still a matter of debate. The apparently acoelomate organization suggests a relationship with the platyhelminths, whereas the blood-vascular system has been interpreted as an equivalent to coelomic cavities of annelids, indicating a close relation between annelids and nemerteans. Like other spiralians, most nemertean species are known to have one or several pairs of rhabdomeric and subepidermally situated eyes when adult. The development of these eyes as well as the mode in which the eyes are multiplied is as yet unknown. This is the first attempt to investigate eye formation in a nemertean. In the heteronemertean Lineus viridis (Müller, 1774) the everse rhabdomeric eyes are located deeply underneath the epidermis and consist of a few pigment cells that form a cup-like structure with interdigitating processes that contain numerous pigment granules. In hatchlings, the optical cavity contains processes of 12 sensory cells, each bearing a single cilium and various microvilli. The perikarya of these cells are located distally from the pigment cup. During further development the number of cells increases. Eye development starts with a small anlage situated underneath the epidermis, irrespective of whether this is the first eye or any additional one. The anlage consists of five unpigmented cells and three dendritic processes, each bearing apical microvilli and a single cilium. There is no evidence for an epidermal origin of the eyes. In L. viridis eye formation resembles that described in platyhelminths in which eyes also develop as cerebral derivatives. Although this result has the potential to influence the discussion on the position of Nemertea, the data have to be interpreted with care, since development of L. viridis is derived within the Nemertea.     

施肥对台湾桤木-扁穗牛鞭草复合模式下桤木细根形态特征、生物量及组织碳氮含量的影响

细根具有良好的可塑性, 不同根序等级的细根会表现不同的策略来适应土壤资源有效性的改变, 了解各级细根对土壤资源有效性的可塑性反应对认识细根的养分和水分吸收规律、预测碳(C)在地下的分配特点具有重要意义。该文以四川省丹陵县台湾桤木(Alnus formosana)-扁穗牛鞭草(Hemarthria compressa)复合模式为研究对象, 采用施肥处理, 应用土柱法采样, 探讨了施肥对台湾桤木-扁穗牛鞭草模式土壤表层(0-10 cm)和亚表层(10-20 cm)台湾桤木1-5级细根的生物量、形态特征(直径、比根长)、全C和全氮(N)含量的影响。结果表明: (1)台湾桤木1-5级细根直径随根序的增大而增加, 施肥降低土壤表层台湾桤木各级细根直径而增加了土壤亚表层台湾桤木各级细根直径; 台湾桤木1-5级细根比根长则随根序的增加而减小, 施肥增加了台湾桤木各级细根的比根长, 且施肥极显著增加了表层和亚表层台湾桤木前三级细根的比根长(p < 0.01)。(2)台湾桤木1-5级细根生物量均随土层深度的增加而减小, 施肥减少了台湾桤木各个土层各级细根生物量, 且显著降低了台湾桤木前三级细根生物量占总生物量的比例(p < 0.05), 而增加了4、5级细根生物量。(3)台湾桤木3级细根全C最大, 1级根最小, 且土壤表层台湾桤木各级细根全C含量大于亚表层; 施肥降低了台湾桤木各级细根全C含量, 但影响并不显著(p > 0.05)。台湾桤木细根全N含量随根序的增加而降低, 且土壤表层1-5级细根全N含量均高于亚表层; 施肥极显著(p < 0.01)增加了土壤表层1级细根及亚表层1、2级细根的全N含量, 而对于3-5级细根全N含量则影响不显著(p > 0.05)。以上结果显示, 当土壤资源有效性变化时, 各级根序细根会作出不同的可塑性反应, 且施肥对各级细根的影响主要表现在低级根上。     

Monocotyledon fruits and seeds, and an associated palynoflora from Eocene-Oligocene sediments of coastal central Queensland, Australia

Fruits of Restionaceae and seeds of Typhaceae are described from a latest Eocene–Oligocene mudstone underlying oil shales in a subsurface sequence near Rockhampton, coastal central Queensland. The Restionaceae fruits are unilocular and encase a single pendulous orthotropous seed with a structured micropylar cap, which may be tannin filled. These are allocated to Restiocarpum gen. nov., which has as its type Restiocarpum latericum sp. nov., and four other taxa described herein; Restiocarpum tesselatum sp. nov., Restiocarpum verrucatum sp. nov., Restiocarpum laeve sp. nov., and Restiocarpum fusiforme sp. nov. Typhaspermum cooksoniae gen. et sp. nov., which accommodates asymmetric claviform seeds, is interpreted as a member of the Typhaceae based on the presence of a lid-like operculum, bitegmic wall, and chalazal cavity.

Reconstruction of the source plant community emphasizes similarities to restiad swamps of present day Wallum (swamp heathland) vegetation which is extensively developed along the Queensland coast. Biogeographic implications for the Restionaceae and Typhaceae are discussed.     

Tracks and trackways of Myotragus balearicus Bate (Artiodactyla, Caprinae) in Pleistocene aeolianites from Mallorca (Balearic Islands, Western Mediterranean)

Tracks and trackways of the ruminant goat, Myotragus balearicus Bate, 1909 are abundant in the Late Pleistocene aeolianites of the south coast of Mallorca, Spain. The carbonate aeolianites form impressive dunes and related sand ramps that were initiated as echo dunes in front of a 20–40 m high paleocliff of Miocene reefal limestone. Where the dunes built up to the cliff top, they covered it as an aeolian ramp. The dunes and sand ramps were active during the dry summer months but were passive during the wet winter period. The small, goat-like animals were abundant on the island, and for unknown reasons crossed the aeolian accumulations in large numbers. This study deals with the tracks formed in the dune deposits. All preserved trackways indicate impression into moist sand. Special features of the tracks include the structure produced by the withdrawal of the foot, here called the ‘axis’, and a disturbance zone of plastic deformation around this. On dune crests, the disturbance zone surrounds the axis more or less symmetrically. However, in addition, a ‘pressure pad’ of dislocated, slightly rotated sediment bound by curved microfaults is commonly produced posterior to the axis by propulsive pressure of the foot. On steep stoss and lee slopes, the pressure pad becomes oriented in a down-slope position as a result of gravitational slip of the walking animal. Combination of disturbance of the sediment in this way by manus followed by overprinting of similar disturbance by pes produces highly complicated track structure. This structure may be characteristic of artiodactylous mammals in soft sand, particularly aeolian deposits. The structure is designated as Bifidipes aeolis isp. nov.     

富营养化水体中自然食物对透明溞(Daphnia hyalina)生长与繁殖影响的初步实验

以广东省流溪河水库中分离驯化的透明溞为研究对象,通过喂养来自富营养化湖泊(暨南大学明湖)的自然食物,探讨富营养化水体中的食物对透明溞生长与繁殖的影响。来自明湖的4种自然食物分别由2个网孔为38μm和110μm的浮游生物网过滤所得的,并将这2种过滤水稀释3倍后得到另外2种食物。在4种明湖自然食物培养条件下,透明溞最大体长、体长生长率和寿命均随食物浓度的稀释而下降,最大体长为2.63mm,最高体长生长率为0.0314mm·d^-1,最长寿命为65d。稀释后食物培养的透明溞,首次怀卵个体体长为1.46mm,大于非稀释食物条件下首次怀卵个体体长1.28mm;在110μm过滤的非稀释食物条件下,内禀增长率达到最大值为0.42。本实验结果表明,冬季富营养水体中食物对透明溞生长与繁殖没有产生抑制作用,食物浓度对透明溞的生长与繁殖的影响高于食物大小的影响。     

鮸形态性状与体质量的关系

为了研究鮸的形态性状与体质量之间的关系,测量了524尾12月龄左右鮸的体质量(Y, g)和8个形态性状(cm),包括全长(X₁)、体长(X₂)、头长(X₃)、躯干长(X₄)、尾长(X₅)、尾柄长(X₆)、尾柄高(X₇)和体高(X₈).采用相关分析、回归分析、通径分析以及模型拟合等方法对其进行分析.结果表明: 鮸所有性状两两之间存在极显著正相关关系,相关系数在0.834～0.941.经共线性诊断排除了体长这一具有严重共线性的性状后,采用逐步引入-剔除法进行多元回归并进行显著性检验,成功筛选出全长(X₁)、躯干长(X₄)、尾柄高(X₇)和体高(X₈)4个统计检验极显著的形态性状,并建立多元回归方程:Y ＝-444.188 +7.943X₁ +12.861X₄ +38.254X₇ + 42.722X₈.通径分析结果显示,4个形态性状中,体高对体质量的直接作用最大(通径系数=0.351),全长次之(通径系数=0.335).对全长和体高与体质量之间的函数关系进行曲线模型拟合得出,在6个拟合模型中,幂函数模型拟合效果最好,方程为:y=0.013 x^2.891(全长); y=2.028 x^2.751(体高).经适合性检验得知,全长比体高通过幂函数对体质量的预测效果更好.研究结果可为鮸的形态性状在选择育种中的有效利用提供重要参考.     

Biogeography and incipient speciation in Ophryotrocha labronica (Polychaeta, Dorvilleidae)

Crossing experiments were conducted between the Naples I (NI) strain of Ophryotrocha labronica labronica, three strains of O. l. pacifica from Japan (M3), Hawaii (WH) and Los Angeles (LA), two strains of O. labronica from Australia and one from an unknown origin, discovered in a Moscow aquarium, to determine the relationships between the European and Pacific subspecies, and the newly discovered strains. Previously published data combined with new results revealed several stages in the process of speciation within the sibling group. Interpopulation crosses yielded an increased sex ratio that appears to be positively related to genetic distance and to the sex ratio of the parent strains. Fecundity data demonstrated that the three northern Pacific strains are more closely related to each other than to any other strain, confirming that they are a valid subspecies, and indicate that they are the result of natural distribution. The strain of unknown origin as well as the Australian strains clearly belong to O. l. labronica. Its isolated presence in the South Pacific may be a remnant of an earlier wider distribution or an introduction of the Mediterranean population, as the life histories of Ophryotrocha species have made them prime candidates for anthropogenic dispersals.     

Vertical sections through dinosaur tracks (Late Triassic lake deposits, East Greenland) – undertracks and other subsurface deformation structures revealed

Tracks and trackways of theropod dinosaurs (Grallator footprints) are abundant in the Late Triassic lake sediments of East Greenland. For this study we selected a rather diffuse theropod track preserved on the upper surface of a red heterolithic mudrock, and a better preserved track seen on the upper surface of a greyish mudrock. In order to examine undertracks and other subsurface deformation structures, both slabs were sectioned vertically at closely-spaced intervals, perpendicular to the length of the axis of the impression of digit III. Each section was subsequently polished and internal structures revealed. The digit impressions of both tracks were associated with well-defined undertracks which were cut by deep and narrow claw imprints at the distal end of the digit impressions. Marginal ridges at the tracking surfaces were typically associated with subsurface marginal folds. The marginal ridges were asymmetrically developed suggesting an outward movement of the proximal part of the foot, probably during the kick-off; this is in contrast to what is observed in tracks from Lower Jurassic theropods. The study shows that cross-sections through dinosaur tracks display large structural variation and it is suggested that some disturbed layers in continental deposits could be the result of trampling by vertebrates.     

云南松苗木生长与生物量的相关性及通径分析

为了解云南松苗木生长对生物量的影响程度和相对重要性,以采自云南省昆明市宜良县禄丰村林场种子培育的2年生云南松苗木为材料,对苗高、地径、主根长、侧根长、针叶长和侧根数6个生长性状及各组分生物量进行测定,运用相关性分析和逐步回归分析剔除了对生物量影响不大的性状,在此基础上采用通径分析方法研究了云南松苗木生长性状指标与生物量指标间的关系。结果表明：云南松苗木生长性状和生物量之间均呈现极显著的正相关关系。各生长性状对生物量均有直接或间接的正向效应,直接影响云南松苗木生物量的优势因素为地径和苗高,针叶长、侧根长和主根长对生物量的影响也起正向效应。各生长性状对生物量的直接效应均较大,而通过其他性状的间接效应均较小,其中侧根长通过其他性状对生物量产生的间接影响最大。依据相关性分析和通径分析,建立了云南松各组分生物量与生长性状之间的数学模型,可用于云南松苗期生物量的估测。     

Current understanding of UV-induced base pair substitution mutation in E. coli with particular reference to the DNA polymerase III complex

UV mutagenesis in E. coli is believed to occur in two discrete steps. The second step involves continued DNA synthesis beyond a blocking lesion in the template strand. This bypass step requires induced levels of umuD and umuC gene products and activated recA protein. DNA polymerase III may be involved since a dnaE mutator strain (believed to have defective base selection) is associated with enhanced UV mutagenesis in conjunction with a genetic background permitting the bypass step. In non-UV-mutable umu and lexA strains, UV mutagenesis can be demonstrated if delayed photorevesal is given. This is interpreted as indicating that an earlier misincorporation step can occur in such strains but the resulting mutations do not survive because the bypass step is blocked. The misincorporation step does not require any induced SOS gene products and can occur either at the replication fork or during repair replication following excision of a DNA lesion. Neither a dnaE mutator gene (leading to a defective subunit of DNA polymerase III holoenzyme) nor a mutD5 mutator gene (leading to a defective ε proofreading subunit) had any effect on he misincorporation step. Although this is consistent with DNA polymerase III holoenzyme not being involved in the misincorporation step, other interpretations involving the inhibition of ε proofreading activity by recA protein are possible.

In vitro studies are reported in which sites of termination of synthesis by DNA polymerase III holoenzyme on UV-irradiated M13 mp8 DNA were examined in the presence of inhibitors of the 3′–5′ proofreading exonuclease (including recA protein). No evidence was found for incorporation of bases opposite photoproducts suggesting that either inhibition is more complete in the cell and/or that other factors are involved in the misincorporation step.     

Biostratigraphy, biodiversity and palaeoenvironments of the chitinozoans and associated palynomorphs from the Upper Ordovician of the Central Anti-Atlas, Morocco

The range, abundance and diversity of Upper Ordovician chitinozoans and of various other organic-walled microfossils (i.e., acritarchs, leiospheres, scolecodonts) have been documented in the Bou-Ingarf section, Central Anti-Atlas, Morocco. The goal of this study is to provide a refined biostratigraphic scheme for the Lower Ktaoua, the Upper Tiouririne, the Upper Ktaoua and the Lower Second Bani formations in order to locate the initial effects of the Late Ordovician glaciation on the composition of assemblages of organic-walled microfossils. Five Late Ordovician chitinozoan biozones belonging to the North Gondwana zonation are identified. During the late Caradoc and early Ashgill, no significant changes in chitinozoan assemblages are recorded that could be attributed to any dramatic climatic and/or environmental events. The almost absence of phytoplanktonic elements (acritarchs and leiospheres) and of cryptospores in the fistulosa/barbata and in the nigerica biozones are interpreted as resulting of lower offshore environmental conditions. The reappearance of a variety of palynomorphs in the lower part of the elongata biozone does not indicate drastic climatic changes but more likely a shallowing trend of the marine environment and an increased primary production, possibly related to a cooling of the surface water masses subsequently to early effects of a general climatic cooling. The first obvious evidence of the Late Ordovician glaciation occurs in the lower part of the elongata biozone, at the base of the sandy member topping the Lower Second Bani Formation. This sandy deposit is interpreted as the result of a dramatic fall of the sea level due to the development of the Hirnantian ice cap on Gondwana. This short-lived glaciation ended when the northern Gondwanan ice cap melted during the upper part of the elongata and the oulebsiri biozones. A biological crisis affected both the chitinozoans and the acritarchs just after this glaciation, i.e., in the latest Hirnantian.     

Responses of the Circadian Locomotor Activity Rhythm of Mus Booduga to Shifts in LD Schedules

The responses of the field mouse Mus booduga to shifts in schedules of LD cycles were monitored and the results were interpreted with the help of a PRC constructed for the same species. The results reveal that, M. booduga reentrained faster with a lesser number of transients after delay shifts than advance shifts, thus exhibiting “asymmetry effect.” A positive correlation was observed between the number of transients and the number of hours of shift. In most of the shifts, the sign of the transients (negative for delaying transients and positive for advancing transients) coincided with the direction of the shift. Interestingly, 11 and 12 h of advance shifting resulted in delaying transients. An 11-h advance shift can also be interpreted as a 13-h delay. Reentrainment through delaying transients is faster as compared to reentrainment through advancing transients. Thus, this animal might have taken a “shorter route,” as proved by the fact that an 11-h advance shift has evoked delaying transients. But a 13-h advance shift evoked only advancing transients. This prompts us to speculate that there may be a “phase jump” in M. booduga. Further, irrespective of whether L or D has been doubled in a 12-h shift, both evoked only delaying transients.     

The mixosaurid ichthyosaur Contectopalatus from the Middle Triassic of the German Basin

The skull of the mixosaurid species Contectopalatus atavus (Quenstedt, 1851-52) is the most bizarre of any known ichthyosaur. It possesses a very high sagittal crest formed by the nasal, frontal and parietal bones which grows higher during ontogeny. This skull structure - found to a lesser extent in the other mixosaurid genera Mixosaurus and Phalarodon - is a synapomorphy of the family Mixosauridae. It is here interpreted as correlated with a unique arrangement of the jaw adductor musculature among tetrapods, with the internal jaw adductors extending over most of the skull roof up to the external narial opening. This reconstruction would increase the biting force considerably and the hypothesis is supported by peculiarities of the dentition and jaws of Contectopalatus. Contectopalatus probably reached a length of about 5 meters. It is therefore the largest known mixosaurid and one of the largest Triassic ichthyosaurs. The general text-book picture of mixosaurs as small, rather unspecialized, primitive ichthyosaurs is incorrect. Mixosaurs were a highly specialized, uniquely adapted and very diverse ichthyosaur family, some members of which rank among the marine top predators of their time.     

Hierarchy,spatial configuration,and nutrient cycling in a desert stream

Abstract Recent studies of nutrient cycling in Sycamore Creek in Arizona, USA, suggest that a thorough understanding requires a spatially explicit, hierarchical approach. Physical configuration determines the path that water follows as it moves downstream. Water follows flowpaths through surface stream components, the hyporheic zone beneath the surface stream, and the parafluvial (sand bar) zone. Characteristic biogeochemical processes in these subsystems alter nitrogen (N) species in transport, in part as a function of available concentrations of N species. At several hierarchical levels, substrate materials are an important determinant of nitrogen dynamics in desert streams. Sand is present in bars of variable size and shape, each of which can be considered a unit, interacting with the surface stream. Groups of these stream-sandbar units form a higher level, the reach. At the next higher scale, sandy reaches (runs) alternate with riffles. Where flowpaths converge, rates of N transformation are high and, as a result, change in concentration is a non-linear function of flowpath length. Disturbance by flash floods alters sandbar configuration. Between floods, the interaction of subsurface and surface flowpaths shapes configuration in each, thus a self-organizing element of spatial structure exists. Sandy runs are dominated by subsurface processes and are likely to be net nitrifiers while riffles are dominated by surface flow and are nitrogen fixers. Whether a stream ecosystem retains nitrogen, or transports it to downstream recipient systems, or is a net emitter of gaseous forms of N, depends upon the dynamics of a spatial mosaic of interacting elements. An understanding of the net effect of this mosaic requires a spatially explicit, hierarchical, multi-scale approach.     

Elongation correlates with nutrient deprivation in Pseudomonas aeruginosa-unsaturates biofilms

Bacteria in nature frequently grow as biofilms, yet little is known regarding how biofilm bacteria morphologically adapt to low nutrient availability, which is common in unsaturated environments such as the terrestrial subsurface or on plant leaves. For unsaturated biofilms, in which the substratum may provide all nutrients, what are the relationships between nutrition and cell size and shape-the simplest metrics of cellular morphology? To address this question, we cultured Pseudomonas aeruginosa, a ubiquitous gram-negative bacterium that is environmentally and medically important, on membranes overlaying solid media, and then measured cellular dimensions using atomic force microscopy (AFM). Nutrition was controlled chemically by media composition and physically by stacking membranes to increase the path length for nutrient diffusion. Under conditions of carbon-nitrogen imbalance, low carbon bioavailability, or increased nutrient diffusional path length, cells elongated while maintaining constant width. A mathematical relationship suggests that, by elongating, biofilm bacteria strategically enlarge their nutrient collection surface without substantially changing the ratio of surface area to volume (SA/V). We conclude that P. aeruginosa growing as unsaturated biofilm with a planar nutrient source morphologically adapt to starvation by elongating. This adaptation, if generalizable, differs from a better-understood starvation response (i.e., cell size decreases; thus SA/V in-creases) for planktonic bacteria in well-mixed environments.     

A new simplified assay for larval migration inhibition

, , , and 1992. A new simplified assay for larval migration inhibition. International Journal for Parasitology 22: 1183–1185. A simple method is described for the in vitro detection of substances that impair the motility of third-stage larvae of gastro-intestinal nematodes. The test is based on the ability of larvae to freely migrate through selected mesh sizes of nylon sieves and the reduced ability of larvae to migrate after preincubation with, and in the presence of, substances that inhibit or reduce larval motility.     

Cuticular ultrastructure of Chordodes nobilii Camerano, 1901, with a comparison of cuticular ultrastructure in horsehair worms (Nematomorpha)

The cuticle of Chordodes nobilii Camerano, 1901 is composed of a proximal layer with about 30 sheets of large fibers in alternating orientations and a distal layer, which mainly forms the surface structures, the areoles. The three different types of areoles, simple, tubercle and crowned areoles, are formed mainly by material of strong and medium electron density. The tubercle areoles have a basal constriction and paired spherical structures of unknown function below the base. Irregularly distributed are paired, cushion-like structures, from which projections traverse the cuticle and run into the epidermis. In the crowned areoles, these cushions also send projections into the apical filaments. A comparison with the few ultrastructurally described cuticles from other species reveals some similarities between the cuticles of C. nobilii and Paragordius varius, making it probable that the cushion-like structures are homologous. However, Pseudochordodes bedriagae, which is more closely related to Chordodes than Paragordius, lacks the cushions. Problematic is the interpretation of different cuticular structures in Gordius. If correctly determined, areoles are present in some Gordius species and resemble in their structure areoles from other species. If areoles have to be regarded as homologous, the absence of a distal layer and areoles would have to be interpreted as a secondary reduction in species such as Gordius aquaticus.     

Mutagenic DNA repair in Escherichia coli, XX. Overproduction of UmuD'' protein results in suppression of the umuC36 mutation in excision defective bacteria

Overproduction of Umu⁺ or UmuD′ protein by means of a gene carried on a multicopy plasmid suppressed the umuC36 phenotype and permitted induction of mutations by ultraviolet light. The umuC122::Tn5 phenotype was not suppressed. Suppression of the umuC36 phenotype was only seen when excision repair was blocked by acriflavine or by an uvrA or uvrB mutation. Cleavage of UmuD to UmuD′ in SOS-induced cells was not dependent upon the presence of UmuC protein. The results are interpreted in terms of a revised model in which UmuC protein is envisaged as guiding UmuD′ to ReA protein which has recognized and become bound to an appropriate DNA lesion. It is suggested that the umuC36 mutation gives rise to a protein with reduced affinity for UmuD′ and that the effect of this can be compensated by an excess of UmuD′.     

Decolorization of textile indigo dye by ligninolytic fungi

The indigo dye is extensively used by textile industries and is considered a recalcitrant substance, which causes environmental concern. Chemical products used on textile processing, which affect the environment through effluents, can be voluminous, colored and varied. Vat textile dyes, like indigo, are often used and dye mainly cellulosic fibers of cotton. Decolorization of this dye in liquid medium was tested with ligninolytic basidiomycete fungi from Brazil. Decolorization started in a few hours and after 4 days the removal of dye by Phellinus gilvus culture was in 100%, by Pleurotus sajor-caju 94%, by Pycnoporus sanguineus 91% and by Phanerochaete chrysosporium 75%. No color decrease was observed in a sterile control. Thin layer chromatography of fungi culture extracts revealed only one unknown metabolite of Rf=0.60, as a result of dye degradation.